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As climate writers, my colleagues and I spend a lot of time telling readers that places are hot. The Arabian Peninsula? It’s hot. The Atlantic Ocean? It’s hot. The southern U.S. and northern Mexico? Hot and getting hotter.
But here’s a little secret: “Hot” doesn’t really mean … anything. The word is, of course, of critical importance when it comes to communicating that global temperatures are the highest they’ve been in 125,000 years because of greenhouse gases in the atmosphere, or for public health officials to anticipate and prevent deaths when the environment reaches the point where human bodies start malfunctioning. But when you hear it’s “100 degrees out,” what does that really tell you?
Beyond that you’re a fellow member of the Fahrenheit cult, the answer is: not a lot. Humans can “probably avoid overheating” in temperatures of 115 degrees — but only if they’re in a dry room with 10 percent relative humidity, wearing “minimal” clothing, and not moving, The New York Times reports. On the other hand, you have a high chance of life-threatening heat stroke when it’s a mere 90 degrees out … if the humidity is at 95%. Then there are all the variables in between: if there’s a breeze, if you’re pregnant, if you’re standing in the shade or the sun, if you’re a child, if you’re running a 10K or if you’re napping on your couch in front of a swamp cooler.
In order to better specify how hot “hot” is, a number of different equations and techniques have been developed around the world. In general, this math takes into account two main variables: temperature (the one we all use, also known as “dry bulb” or “ambient air temperature,” which is typically measured five feet above the ground in the shade) and relative humidity (the percentage of air saturated with water vapor, also known as the ugly cousin of the trendier dew point; notably Canada’s heat index equivalent, the Humidex, is calculated from the dew point rather than the relative humidity).
In events like the already deadly heat dome over the southern United States and northern Mexico this week, you typically hear oohing and ahhing about the “heat index,” which is sometimes also called the “apparent temperature,” “feels like temperature,” “humiture,” or, in AccuWeather-speak, the “RealFeel® temperature.”
But what does that mean and how is it calculated?
The heat index roughly approximates how hot it “actually feels.”
This is different than the given temperature on the thermometer because the amount of humidity in the air affects how efficiently sweat evaporates from our skin and in turn keeps us cool. The more humidity there is, the less efficiently our bodies can cool themselves, and the hotter we feel; in contrast, when the air is dry, it’s easier for our bodies to keep cool. Regrettably, this indeed means that insufferable Arizonans who say “it’s a dry heat!” have a point.
The heat index, then, tells you an estimate of the temperature it would have to be for your body to be similarly stressed in “normal” humidity conditions of around 20%. In New Orleans this week, for example, the temperature on the thermometer isn’t expected to be above 100°F, but because the humidity is so high, the heat toll on the body will be as if it were actually 115°F out in normal humidity.
Importantly, the heat index number is calculated as if you were standing in the shade. If you’re exposed to the sun at all, the “feels like” is, of course, actually higher — potentially as many as 15 degrees higher. Someone standing in the New Orleans sun this week might more realistically feel like they’re in 130-degree heat.
The heat index graph.NOAA
Here’s the catch, though: The heat index is “purely theoretical since the index can’t be measured and is highly subjective,” as meteorologist Chris Robbins explains. The calculations are all made under the assumption that you are a 5’7”, 147-pound healthy white man wearing short sleeves and pants, and walking in the shade at the speed of 3.1 mph while a 6-mph wind gently ruffles your hair.
Wait, what?
I’m glad you asked.
In 1979, a physicist named R. G. Steadman published a two-part paper delightfully titled “The Assessment of Sultriness.” In it, he observed that though many approaches to measuring “sultriness,” or the combined effects of temperature and humidity, can be taken, “it is best assessed in terms of its physiological effect on humans.” He then set out, with obsessive precision, to do so.
Steadman came up with a list of approximately 19 variables that contribute to the overall “feels like” temperature, including the surface area of an average human (who is assumed to be 1.7 meters tall and weigh 67 kilograms); their clothing cover (84%) and those clothes’ resistance to heat transfer (the shirt and pants are assumed to be 20% fiber and 80% air); the person’s core temperature (a healthy 98.6°F) and sweat rate (normal); the effective wind speed (5 knots); the person’s activity level (typical walking speed); and a whole lot more.
Here’s an example of what just one of those many equations looked like:
One of the many equations in “The Assessment of Sultriness: Part I,”R.G. Steadman
Needless to say, Steadman’s equations and tables weren’t exactly legible for a normal person — and additionally they made a whole lot of assumptions about who a “normal person” was — but Steadman was clearly onto something. Describing how humidity and temperature affected the human body was, at the very least, interesting and useful. How, then, to make it easier?
In 1990, the National Weather Service’s Lans P. Rothfusz used multiple regression analysis to simplify Steadman’s equations into a single handy formula while at the same time acknowledging that to do so required relying on assumptions about the kind of body that was experiencing the heat and the conditions surrounding him. Rothfusz, for example, used Steadman’s now-outdated calculations for the build of an average American man, who as of 2023 is 5’9” and weighs 198 pounds. This is important because, as math educator Stan Brown notes in a blog post, if you’re heavier than the 147 pounds assumed in the traditional heat index equation, then your “personal heat index” will technically be slightly hotter.
Rothfusz’s new equation looked like this:
Heat index = -42.379 + 2.04901523T + 10.14333127R - 0.22475541TR - 6.83783x10-3T 2 - 5.481717x10-2R 2 + 1.22874x10-3T 2R + 8.5282x10-4TR2 - 1.99x10-6T 2R 2
So much easier, right?
If your eyes didn’t totally glaze over, it actually sort of is — in the equation, T stands for the dry bulb temperature (in degrees Fahrenheit) and R stands for the relative humidity, and all you have to do is plug those puppies into the formula to get your heat index number. Or not: There are lots of online calculators that make doing this math as straightforward as just typing in the two numbers.
Because Rothfusz used multiple regression analysis, the heat index that is regularly cited by the government and media has a margin of error of +/- 1.3°F relative to a slightly more accurate, albeit hypothetical, heat index. Also of note: There are a bunch of different methods of calculating the heat index, but Rothfusz’s is the one used by the NWS and the basis for its extreme heat alerts. The AccuWeather “RealFeel,” meanwhile, has its own variables that it takes into account and that give it slightly different numbers.
Midday Wednesday in New Orleans, for example, when the ambient air temperature was 98°F, the relative humidity was 47%, and the heat index hovered around 108.9°F, AccuWeather recorded a RealFeel of 111°F and a RealFeel Shade of 104°F.
You might also be wondering at this point, as I did, that if Steadman at one time factored out all these variables individually, wouldn’t it be possible to write a simple computer program that is capable of personalizing the “feel like” temperature so they are closer to your own physical specifications? The answer is yes, although as Randy Au writes in his excellent Substack post on the heat index equation, no one has seemingly actually done this yet. Math nerds, your moment is now.
Because we’re Americans, it is important that we use the weirdest possible measurements at all times. This is probably why the heat index is commonly cited by our government, media, and meteorologists when communicating how hot it is outside.
But it gets weirder. Unlike the heat index, though, the “wet-bulb globe temperature” (sometimes abbreviated “WBGT”) is specifically designed to understand “heat-related stress on the human body at work (or play) in direct sunlight,” NWS explains. In a sense, the wet-bulb globe temperature measures what we experience after we’ve been cooled by sweat.
The Kansas State High School Activities Association thresholds for wet-bulb globe temperature.Weather.gov
The “bulb” we’re referring to here is the end of a mercury thermometer (not to be confused with a lightbulb or juvenile tulip). Natural wet-bulb temperature (which is slightly different from the WBGT, as I’ll explain in a moment) is measured by wrapping the bottom of a thermometer in a wet cloth and passing air over it. When the air is dry, it is by definition less saturated with water and therefore has more capacity for moisture. That means that under dry conditions, more water from the cloth around the bulb evaporates, which pulls more heat away from the bulb, dropping the temperature. This is the same reason why you feel cold when you get out of a shower or swimming pool. The drier the air, the colder the reading on the wet-bulb thermometer will be compared to the actual air temperature.
Wet bulb temperature - why & when is it used?www.youtube.com
If the air is humid, however, less water is able to evaporate from the wet cloth. When the relative humidity is at 100% — that is, the air is fully saturated with water — then the wet-bulb temperature and the normal dry-bulb temperature will be the same.
Because of this, the wet-bulb temperature is usually lower than the relative air temperature, which makes it a bit confusing when presented without context (a comfortable wet-bulb temperature at rest is around 70°F). Wet-bulb temperatures over just 80, though, can be very dangerous, especially for active people.
The WBGT is, like the heat index, an apparent temperature, or “feels like,” calculation; generally when you see wet-bulb temperatures being referred to, it is actually the WBGT that is being discussed. This is also the measurement that is preferred by the military, athletic organizations, road-race organizers, and the Occupational Safety and Health Administration because it helps you understand how, well, survivable the weather is, especially if you are moving.
Our bodies regulate temperature by sweating to shed heat, but sweat stops working “once the wet-bulb temperature passes 95°F,” explains Popular Science. “That’s because, in order to maintain a normal internal temperature, your skin has to stay at 95°F degrees or below.” Exposure to wet-bulb temperatures over 95°F can be fatal within just six hours. On Wednesday, when I was doing my readings of New Orleans, the wet-bulb temperature was around 88.5°F.
The WBGT is helpful because it takes the natural wet-bulb temperature reading a step further by factoring in considerations not only of temperature and humidity, but also wind speed, sun angle, and solar radiation (basically cloud cover). Calculating the WBGT involves taking a weighted average of the ambient, wet-bulb, and globe temperature readings, which together cover all these variables.
That formula looks like:
Wet-bulb globe temperature = 0.7Tw + 0.2Tg + 0.1Td
Tw is the natural wet-bulb temperature, Tg is the globe thermometer temperature (which measures solar radiation), and Td is the dry bulb temperature. By taking into account the sun angle, cloud cover, and wind, the WBGT gives a more nuanced read of how it feels to be a body outside — but without getting into the weeds with 19 different difficult-to-calculate variables like, ahem, someone we won’t further call out here.
Thankfully, there’s a calculator for the WBGT formula, although don’t bother entering all the info if you don’t have to — the NWS reports it nationally, too.
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Half of all Americans are sweating under one right now.
Like a bomb cyclone, a polar vortex, or an atmospheric river, a heat dome is a meteorological phenomenon that feels, well, a little made up. I hadn’t heard the term before I found myself bottled beneath one in the Pacific Northwest in 2021, where I saw leaves and needles brown on living trees. Ultimately, some 1,400 people died from the extreme heat in British Columbia, Washington, and Oregon that summer weekend.
Since that disaster, there have been a number of other high-profile heat dome events in the United States, including this week, over the Midwest and now Eastern and Southeastern parts of the country. On Monday, roughly 150 million people — about half the nation’s population — faced extreme or major heat risks.
“I think the term ‘heat dome’ was used sparingly in the weather forecasting community from 10 to 30 years ago,” AccuWeather senior meteorologist Brett Anderson told me, speaking with 36 years as a forecaster under his belt. “But over the past 10 years, with global warming becoming much more focused in the public eye, we are seeing ‘heat dome’ being used much more frequently,” he went on. “I think it is a catchy term, and it gets the public’s attention.”
Catching the public’s attention is critical. Heat is the deadliest weather hazard in the U.S., killing more people annually than hurricanes, floods, tornadoes, or extreme cold. “There is a misunderstanding of the risk,” Ashley Ward, the director of the Heat Policy Innovation Hub at Duke University, told me. “A lot of people — particularly working age or younger people — don’t feel like they’re at risk when, in fact, they are.”
While it seems likely that the current heat dome won’t be as deadly as the one in 2021 — not least because the Midwest and Southeastern regions of the country have a much higher usage of air conditioning than the Pacific Northwest — the heat in the eastern half of the country is truly extraordinary. Tampa, Florida reached 100 degrees Fahrenheit on Sunday for the first time in its recorded history. Parts of the Midwest last week, where the heat dome formed before gradually moving eastward, hit a heat index of 128 degrees.
Worst of all, though, have been the accompanying record-breaking overnight temperatures, which Ward told me were the most lethal characteristics of a heat dome. “When there are both high daytime temperatures and persistently high overnight temperatures, those are the most dangerous of circumstances,” Ward said.
Although the widespread usage of the term “heat dome” may be relatively new, the phenomenon itself is not. The phrase describes an area of “unusually strong” high pressure situated in the upper atmosphere, which pockets abnormally warm air over a particular region, Anderson, the forecaster, told me. “These heat domes can be very expansive and can linger for days, and even a full week or longer,” he said.
Anderson added that while he hasn’t seen evidence of an increase in the number of heat domes due to climate change, “we may be seeing more extreme and longer-lasting heat domes” due to the warmer atmosphere. A heat dome in Europe this summer, which closed the Eiffel Tower, tipped temperatures over 115 degrees in parts of Spain, and killed an estimated 2,300 people, has been linked to anthropogenic warming. And research has borne out that the temperatures and duration reached in the 2021 Pacific Northwest heat dome would have been “virtually impossible without human-caused climate change.”
The link between climate change and heat domes is now strong enough to form the basis for a major legal case. Multnomah County, the Oregon municipality that includes Portland, filed a lawsuit in 2023 against 24 named defendants, including oil and gas companies ExxonMobil, Shell, and BP, seeking $50 million in damages and $1.5 billion in future damages for the defendants’ alleged role in the deaths from the 2021 heat dome.
“As we learned in this country when we took on Big Tobacco, this is not an easy step or one I take lightly, but I do believe it’s our best way to fight for our community and protect our future,” Multnomah County Chair Jessica Vega Pederson said in a statement at the time. The case is now in jeopardy following moves by the Trump administration to prevent states, counties, and cities from suing fossil fuel companies for climate damages. (The estate of a 65-year-old woman who died in the heat dome filed a similar wrongful death lawsuit in Seattle’s King County Superior Court against Big Oil.)
Given the likelihood of longer and hotter heat dome events, then, it becomes imperative to educate people about how to stay safe. As Ward mentioned, many people who are at risk of extreme heat might not even know it, such as those taking commonly prescribed medications for anxiety, depression, PTSD, diabetes, and high blood pressure, which interfere with the body’s ability to thermoregulate. “Let’s just say recently you started taking high blood pressure medicine,” Ward said. “Every summer prior, you never had a problem working in your garden or doing your lawn work. You might this year.”
Air conditioning, while life-saving, can also stop working for any number of reasons, from a worn out machine part to a widespread grid failure. Vulnerable community members may also face hurdles in accessing reliable AC. There’s a reason the majority of heat-related deaths happen indoors.
People who struggle to manage their energy costs should prioritize cooling a single space, such as a bedroom, and focus on maintaining a cool core temperature during overnight hours, when the body undergoes most of its recovery. Blotting yourself with a wet towel or washcloth and sitting in front of a fan can help during waking hours, as can visiting a traditional cooling center, or even a grocery store or movie theater.
Health providers also have a role to play, Ward stressed. “They know who has chronic underlying health conditions,” she said. “Normalize asking them about their situation with air conditioning. Normalize asking them, ‘Do you feel like you have a safe place to go that’s cool, that you can get out of this heat?’”
For the current heat dome, at least, the end is in sight: Incoming cool air from Canada will drop temperatures by 10 to 20 degrees in cities like Philadelphia and Washington, D.C., with lows potentially in the 30s by midweek in parts of New York. And while there are still hot days ahead for Florida and the rest of the Southeast, the cold front will reach the region by the end of the week.
But even if this ends up being the last heat dome of the summer, it certainly won’t be in our lifetimes. The heat dome has become inescapable.
On betrayed regulatory promises, copper ‘anxiety,’ and Mercedes’ stalled EV plans
Current conditions: New York City is once again choking on Canadian wildfire smoke • Torrential rain is flooding southeastern Slovenia and northern Croatia • Central Asia is bracing for the hottest days of the year, with temperatures nearing 100 degrees Fahrenheit in Uzbekistan’s capital of Tashkent all week.
In May, the Trump administration signaled its plans to gut Energy Star, the energy efficiency certification program administered by the Environmental Protection Agency. Energy Star is extremely popular — its brand is recognized by nearly 90% of Americans — and at a cost to the federal government of just $32 million per year, saves American households upward of $40 billion in energy costs per year as of 2024, for a total of more than $500 billion saved since its launch in 1992, by the EPA’s own estimate. Not only that, as one of Energy Star’s architects told Heatmap’s Jeva Lange back in May, more energy efficient appliances and buildings help reduce strain on the grid. “Think about the growing demands of data center computing and AI models,” RE Tech Advisors’ Deb Cloutier told Jeva. “We need to bring more energy onto the grid and make more space for it.”
That value has clearly resonated with lawmakers on the Hill. Legislators tasked with negotiating appropriations in both the Senate and the House of Representatives last week proposed fully funding Energy Star at $32 million for the next fiscal year. It’s unclear how the House’s decision to go into recess until September will affect the vote, but Ben Evans, the federal legislative director at the U.S. Green Building Council, said the bill is “a major step in the right direction demonstrating that ENERGY STAR has strong bipartisan support on Capitol Hill.”
A worker connects panels on floating solar farm project in Huainan, China. Kevin Frayer/Getty Images
The United States installed just under 11 gigawatts of solar panels in the first three months of this year, industry data show. In June alone, China installed nearly 15 gigawatts, PV Tech reported. And, in a detail that demonstrates just how many panels the People’s Republic has been deploying at home in recent years, that represented an 85% drop from the previous month and close to a 40% decline compared to June of last year.
The photovoltaic installation plunge followed Beijing’s rollout of two new policies that changed the renewables business in China. The first, called the 531 policy, undid guaranteed feed-in tariffs and required renewable projects to sell electricity on the spot market. That took effect on June 1. The other, called the 430 policy, took effect on May 1 and mandated that new distributed solar farms consume their own power first before allowing the sale of surplus electricity to the grid. As a result of the stalled installations, a top panel manufacturer warned the trade publication Opis that companies may need to raise prices by as much as 10%.
For years now, Fortescue, the world’s fourth-biggest producer of iron ore, has directed much of the earnings from its mines in northwest Australia and steel mills in China toward building out a global green hydrogen business. But changes to U.S. policy have taken a toll. Last week, Fortescue told investors it was canceling its green hydrogen project in Arizona, which had been set to come online next year. It’s also abandoning its plans for a green hydrogen plant on Australia’s northeastern coast, The Wall Street Journal reported.
“A shift in policy priorities away from green energy has changed the situation in the U.S.,” Gus Pichot, Fortescue’s chief executive of growth and energy, told analysts on a call. “The lack of certainty and a step back in green ambition has stopped the emerging green-energy markets, making it hard for previously feasible projects to proceed.” But green hydrogen isn’t dead everywhere. Just last week, the industrial gas firm Air Liquide made a final decision to invest in a 200-megawatt green hydrogen plant in the Netherlands.
The Trump administration put two high-ranking officials at the National Oceanic and Atmospheric Administration on administrative leave, CNN reported. The reasoning behind the move wasn’t clear, but both officials — Steve Volz, who leads NOAA’s satellites division, and Jeff Dillen, NOAA’s deputy general counsel — headed up the investigation into whether President Donald Trump violated NOAA’s scientific integrity policies during his so-called Sharpiegate scandal.
The incident from September 2019, during Trump’s first term, started when the president incorrectly listed Alabama among the states facing a threat from Hurricane Dorian. Throughout the following week, Trump defended the remark, insisting he had been right, and ultimately showed journalists a weather map that had been altered with a black Sharpie market to show the path of the storm striking Alabama. NOAA’s investigation into the incident concluded that Neil Jacobs, the former agency official who backed Trump at the time and is now nominated to serve as chief, succumbed to political pressure and violated scientific integrity rules.
In March, North Carolina’s Republican-controlled Senate passed a bill to repeal the state’s climate law and scrap the 2030 deadline by which the monopoly utility Duke Energy had to slash its planet-heating emissions by 70% compared to 2005 levels. Governor Josh Stein, a Democrat, vetoed the legislation. But on Tuesday, the GOP majorities in both chambers of the legislature plan to vote to override the veto.
Doing so and enacting the bill could cost North Carolina more than 50,000 jobs annually and cause tens of billions of dollars in lost investments, Canary Media’s Elizabeth Ouzts reported. That’s according to a new study from a consultancy commissioned by clean-energy advocates in the state. The analysis is based on data from the state-sanctioned consumer advocate, Public Staff.
For years, a mystery has puzzled scientists: Why did Neanderthal remains show levels of a nitrogen isotope only seen among carnivores like hyenas and wolves that eat more meat than a hominid could safely consume? New research finally points to an answer: Neanderthals were eating putrefying meat garnished with maggots, said Melanie Beasley, an anthropologist at Purdue University. “When you get the lean meat and the fatty maggot, you have a more complete nutrient that you’re consuming.”
Oregon’s Cram Fire was a warning — the Pacific Northwest is ready to ignite.
What could have been the country’s first designated megafire of 2025 spluttered to a quiet, unremarkable end this week. Even as national headlines warned over the weekend that central Oregon’s Cram Fire was approaching the 100,000-acre spread usually required to achieve that status, cooler, damper weather had already begun to move into the region. By the middle of the week, firefighters had managed to limit the Cram to 95,736 acres, and with mop-up operations well underway, crews began rotating out for rest or reassignment. The wildfire monitoring app Watch Duty issued what it said would be its final daily update on the Cram Fire on Thursday morning.
By this time in 2024, 10 megafires had already burned or ignited in the U.S., including the more-than-million-acre Smokehouse Creek fire in Texas last spring. While it may seem wrong to describe 2025 as a quieter fire season so far, given the catastrophic fires in the Los Angeles area at the start of the year, it is currently tracking below the 10-year average for acres burned at this point in the season. Even the Cram, a grassland fire that expanded rapidly due to the hot, dry conditions of central Oregon, was “not [an uncommon fire for] this time of year in the area,” Bill Queen, a public information officer with the Pacific Northwest Complex Incident Management Team 3, told me over email.
At the same time, the Cram Fire can also be read as a precursor. It was routine, maybe, but also large enough to require the deployment of nearly 900 fire personnel at a time when the National Wildland Fire Preparedness Level is set to 4, meaning national firefighting resources were already heavily committed when it broke out. (The preparedness scale, which describes how strapped federal resources are, goes up to 5.) Most ominous of all, though, is the forecast for the Pacific Northwest for “Dirty August” and “Snaptember,” historically the two worst months of the year in the region for wildfires.
National Interagency Coordination Center
“Right now, we’re in a little bit of a lull,” Jessica Neujahr, a public affairs officer with the Oregon Department of Forestry, acknowledged to me. “What comes with that is knowing that August and September will be difficult, so we’re now doing our best to make sure that our firefighters are taking advantage of having time to rest and get rejuvenated before the next big wave of fire comes through.”
That next big wave could happen any day. The National Interagency Fire Center’s fire potential outlook, last issued on July 1, describes “significant fire potential” for the Northwest that is “expected to remain above average areawide through September.” The reasons given include the fact that “nearly all areas” of Washington and Oregon are “abnormally dry or in drought status,” combined with a 40% to 60% probability of above-average temperatures through the start of the fall in both states. Moisture from the North American Monsoon, meanwhile, looks to be tracking “largely east of the Northwest.” At the same time, “live fuels in Oregon are green at mid to upper elevations but are drying rapidly across Washington.”
In other words, the components for a bad fire season are all there — the landscape just needs a spark. Lightning, in particular, has been top of mind for Oregon forecasters, given the tinderbox on the ground. A single storm system, such as one that rolled over southeast and east-central Oregon in June, can produce as many as 10,000 lightning strikes; over the course of just one night earlier this month, thunderstorms ignited 72 fires in two southwest Oregon counties. And the “kicker with lightning is that the fires don’t always pop up right away,” Neujahr explained. Instead, lightning strike fires can simmer for up to a week after a storm, evading the detection of firefighting crews until it’s too late. “When you have thousands of strikes in a concentrated area, it’s bound to stretch the local resources as far as they can go,” Neujahr said.
National Interagency Coordination Center
The National Interagency Fire Center has “low confidence … regarding the number of lightning ignitions” for the end of summer in the Northwest, in large part due to the incredible difficulty of forecasting convective storms. Additionally, the current neutral phase of the El Niño-Southern Oscillation means there is a “wide range of potential lightning activity” that adds extra uncertainty to any predictions. The NIFC’s higher confidence in its temperature and precipitation outlooks, in turn, “leads to a belief that the ratio of human to natural ignitions will remain high and at or above 2024 levels.” (An exploding transformer appears to have been the ignition source for the Cram Fire; approximately 88% of wildfires in the United States have human-caused origins, including arson.)
Periodic wildfires are a naturally occurring part of the Western ecosystem, and not all are attributable to climate change. But before 1995, the U.S. averaged fewer than one megafire per year; between 2005 and 2014, that average jumped to 9.8 such fires per year. Before 1970, there had been no documented megafires at all.
Above-average temperatures and drought conditions, which can make fires larger and burn hotter, are strongly associated with a warming atmosphere, however. Larger and hotter fires are also more dangerous. “Our biggest goal is always to put the fires out as fast as possible,” Neujahr told me. “There is a correlation: As fires get bigger, the cost of the fire grows, but so do the risks to the firefighters.”
In Oregon, anyway, the Cram Fire’s warning has registered. Shortly after the fire broke out, Oregon Governor Tina Kotek declared a statewide emergency with an eye toward the months ahead. “The summer is only getting hotter, drier, and more dangerous — we have to be prepared for worsening conditions,” she said in a statement at the time.
It’s improbable that there won’t be a megafire this season; the last time the U.S. had a year without a fire of 100,000 acres or more was in 2001. And if or when the megafire — or megafires — break out, all signs point to the “where” being Oregon or Washington, concentrating the area of potential destruction, exhausting local personnel, and straining federal resources. “When you have two states directly next to each other dealing with the same thing, it just makes it more difficult to get resources because of the conflicting timelines,” Neujahr said.
By October, at least, there should be relief: The national fire outlook describes “an increasing frequency of weather systems and precipitation” that should “signal an end of fire season” for the Northwest once fall arrives. But there are still a long 68 days left to go before then.