Where the smoke from any of the resulting fires actually goes is far less predictable, however, subject to impossible-to-forecast factors such as when there are human-caused ignitions, how big the fire is, what the winds are doing on a given day or even hour, and how much moisture is in the air, among other micro-factors. What’s actually burning makes a difference, too: trees, logs, and dense forest floor litter, called duff, have more mass than the flash-burning grasses of the Plains, meaning forest fires produce more soot and ash for distribution. “Literally, that is where the heavy emissions come from to get lofted with the intensity of a ground fire,” Pete Lahm, the branch chief for smoke at the U.S. Forest Service and the leader of the Interagency Wildlife Fire Air Quality Response Program, told me.
The current Fort Smith fire in the boreal forest of Canada is an example of how difficult it is to predict smoke exposure. Although northern Canada had a good snow year — which should in theory suppress major fires up there — there was a small pocket of dryness around Wood Buffalo National Park that ignited, ballooned into an almost 40,000-acre fire, and sent high-altitude smoke as far south as Chicago last week. Or take those wildfires in Quebec in 2023, which sent particulate matter as far south as Florida.
“The smoke went out to sea and came back in,” Lahm said of that event. “Who would have thought about that?”
As Will Barrett, the assistant vice president for nationwide clean air policy at the American Lung Association, told me, “No part of the country is immune from the impacts of climate change and the threat of increased pollution.” It’s always best to check your local air quality (which reflects a lot more than just wildfire particulates) and the national fire and smoke map when in doubt.
The West
Smoke forecast: High probability of smoke exposure
Much has already been said by now about the lack of snow in the Western U.S. “This year’s peak snowpack will be the new benchmark low for Wyoming, Utah, Colorado, and New Mexico,” reads the latest National Integrated Drought Information System report from the middle of May. “There are no comparable years.” Idaho, too, has “no historical comparison” for its lack of snow. In the Cascade Mountains and northern Sierras, where some of the country’s worst wildfires have historically occurred, many drought monitoring stations are likewise recording only trace amounts of snow.
Normally, melting snow helps stave off wildfire ignitions through the spring and early summer. When the snow melts too early — or isn’t there in the first place — the potential for explosive wildfires creeps higher much sooner. Forests also just have a lot of stuff — large trees, brushy undergrowth, forest floor leaf litter, homes and cars — which generates a lot of soot and ash.
In the southern half of Nevada and Utah, fuels are already “near or exceeding record dry levels,” per the latest National Significant Wildland Fire Potential Outlook, updated on Monday. What’s more, “Some of the fires are burning in the heavier fuels and timber of higher elevations, which is very unusual for late May” — and causes more smoke than grasses or chaparral.
The report also shows that above-average significant wildfire potential will consume almost the entire northwest corner of the U.S. — all of Washington, Oregon, Idaho, and southwest Montana — by August, and continue into September. The conditions resemble those of 2015, which turned out to be one of the worst fire seasons in Pacific Northwest history, the agency said. Everyone in the region is at risk from local wildfire smoke, regardless of what drifts in from other places.
“If California were to get active, Idaho and parts of Oregon can get slammed with that smoke,” Lahm told me. “Occasionally, with fires in the mid-Sierras, you’ll start to see impacts in Salt Lake City.” That’s especially true when there is above-normal plant growth in the Sacramento Valley and Sierra foothills, as there is this year. (“One sampling site in the Sierra Foothills,” the interagency report found, “recorded the second highest amount of growth in the 43-year period of record.”)
Lahm added a note of potential optimism to the smoke forecast in the West, pointing out that California is not in a severe drought at the moment. Southern California, home of the costliest fire in U.S. history last year, could be spared almost entirely thanks to the expected El Niño-induced above-average rainfall. “Maybe we won’t get the smoke from California this year,” Lahm allowed, before adding, “but California can get drier.”
The South
Smoke forecast: High probability of smoke exposure
The fire season is already well underway in the Southwest, with the airplane-crash-ignited Seven Cabins Fire in New Mexico the biggest active wildfire in the U.S. at 29,000 acres. Local air quality impacts are significant enough that the Forest Service already has air resource advisors involved, but Lahm told me long-range smoke impacts aren’t expected.
The southern and southeastern U.S. can sometimes feel repercussions from fires burning on the West Coast, though. “If we have a good Pacific Rim season, while really volume driven, there have actually been impacts in Louisiana, occasionally,” Lahm said.
Spring fires in Georgia and Florida have burned down into the duff, or “gone underground,” and could reemerge again in the coming months. Late May’s rainstorms could theoretically help curb fires in the Southeast, at least through the early summer. But forecasts show conditions drying out by late summer — El Niño increases wind shear, interrupting hurricane formation in the Atlantic basin and suppressing the tropical storms that normally keep the region wet through the hottest months of the year. Downed trees and brush from Hurricane Helene in 2024 remain an ongoing fire hazard, especially if they dry out.
The Midwest
Smoke forecast: Moderate probability of smoke exposure
The smoke in the Midwest isn’t usually of the homegrown variety, but being downwind of Canada and the western U.S. has made it no stranger to haze and red sunsets. According to the American Lung Association’s 2026 State of the Air report, which looks at the period from 2022-2024, “most of the Midwest” was “seriously impacted by high levels of ozone,” in part due to the “ozone-forming pollutants” generated when wildfire smoke interacts with urban air.
The snow conditions in Canada this year thankfully haven’t followed the pattern in the western U.S., and if things stay relatively wet up north, then it’s less likely the Midwest will experience the boreal wildfire smoke it may otherwise have grown accustomed to. But “say that smoke that came down from the [Fort Smith] fire decided to hit the ground in Chicago” last week, Lahm speculated to me. “It certainly would have probably contributed to [air quality] numbers above the standard, and if you’re sensitive and you’re not ready, then it’s a big deal.”
Because poor air quality often stems from fires burning in other places — which thus are often not top of mind — watching local air quality reports is especially important in the Midwest. No, the Fort Smith smoke didn’t hit Chicago last week, but it could have. More than any other region, the Midwest is a wildcard for smoke impacts.
The East
Smoke forecast: Moderate probability of smoke exposure
Like the Midwest, the Northeast is often the victim of smoke from faraway fires. In 2025, for example, there were what Lahm described as “light impacts” in New York and Washington, D.C., from fires in Quebec, Ontario, and the Western U.S. “because of the volume of fire material being burned.” So far, though, the National Significant Wildland Fire Potential Outlook shows normal fire potential for the Mid-Atlantic region through September with “brief periods of elevated fire danger during windy days that follow dry periods.”
But as I’ve written before, the fire conditions in the East are also changing. The region has seen a 10-fold jump in the frequency of large burns over the past four decades. In fact, almost nowhere better represents the ability of local fires to cause unpredictable regional impacts than the East, where a likely human-caused fire in Brooklyn’s Prospect Park in 2024 sent particulate matter into surrounding neighborhoods.
If smoke defies long-range forecasts, then, the best method is to expect it and be pleasantly surprised if it doesn’t arrive. For most people, that means shaking off any leftover baggage you have around mask-wearing from the COVID-era and keeping a few N95s in the glove box. It also means knowing you’re at risk in the first place. Children under 18, adults over 65, and anyone who is pregnant or has a pre-existing respiratory or heart condition should be especially attuned to their local air quality. For those groups, having extra inhalers on hand or postponing a run could save a life.
“There are not a lot of places in the U.S. where being ready for some degree of smoke exposure, if you’re at risk, doesn’t make sense,” Lahm said. “It’s just good preparation. We keep a flashlight for when the lights go out in our homes — we need to look at smoke the same way.”
California Academy of Sciences
