Sign In or Create an Account.

By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy

Climate

Here Come the Mosquitoes

The bugs are already out in New York and the West is in for ”a very bad spring.” Here’s what experts say is in store for the U.S. this year.

A person running from a giant mosquito.
Heatmap Illustration/Getty Images

It got me in March.

Maybe it happened while I was on a run, enjoying one of the first warm days of spring. Maybe I’d been waiting unsuspectingly for the train on an open-air platform. Maybe it happened in my own apartment. Regardless, at some point last month, I hesitated too long before brushing away a soft, fleeting sensation on my cheek. In the ongoing, 10,000-year-long game of tag between mosquitoes and humans, I’d taken another L.

Though it’s only early April, many New Yorkers have already gotten their first bites of the year: interviewer Isaac Fitzgerald and interviewee James Hannaham were driven out of a backyard by the bugs in Brooklyn; the city’s Department of Health has officially declared “it’s mosquito season in NYC!” and started tweeting out standing-water advisories; and CBS’ local affiliate recently ran a segment about how “it’s going to be a bad summer” for biting insects. Other metropolitan areas are also bracing for a buggy season ahead: “It’s looking like it’s going to be worse than it has [been in] the past two years,” Minnesota’s MPR News reports. “Epic rains expected to take one more swat at California, with masses of mosquitoes,” adds the Los Angeles Times. “We could possibly see more mosquitoes than we wanted to see,” a biologist warned the Ohio area.

Predicting the severity of mosquito season is a bit of an imprecise science, like trying to nail down a long-range weather forecast. Actually, it’s a lot like trying to nail down a long-range weather forecast, since mosquito populations fluctuate based on immediate and unreliable conditions, like spring rainfall and small changes in temperature. Generally speaking, more rain tends to precede “a greater prevalence of mosquitoes within the same month,” while “hotter temperatures [are] associated with increases in mosquitoes one to two months later,” reports one study, which focused on Dengue-carrying Aedes mosquitoes in Sri Lanka. (Invasive Aedes mosquitoes are also found on both U.S. coasts and throughout the South, with their habitats shifting north toward Chicago due to climate change.)

Mosquitos require standing water and temperatures steadily above 50 degrees Fahrenheit in order to start their breeding cycles. In the western United States, in addition to spring rainfall, natural occurrences of standing water are created by snowmelt, which causes floods that dry into perfect mosquito-breeding pools. Snowpack in the West, then, is one of the best early determinants of the coming mosquito season — unfortunate news for Californians, since their state broke a 40-year snowfall record over the winter. “Many places out west where they’ve received record rainfall and snowfall, they’re likely to have a very bad spring,” Daniel Markowski, the technical director of the American Mosquito Control Association, told Heatmap.

Snowmelt can also be a determining factor in the Midwest and East, where fears of spring flooding are already high. That said, their spring mosquito seasons are “less dependent upon the snow” than the West since they “always get at least some snow in many of the same areas,” Markowski went on. The bigger variable for the region is spring rainfall and how early it gets warm.

Mixed news on that front: NOAA expects the East Coast to be warmer than usual from April through June, with above-average precipitation concentrated around the Great Lakes region and potentially stretching south and seaward, through Pennsylvania, New York City, and the D.C.-area. Though the severity of the coming mosquito season is thus still a bit of an unknown, the stakes are high: Last year saw the largest number of ever recorded West Nile virus-positive mosquito pools in New York City, resulting in four deaths. There’s every indication that could happen again in 2023: “We expect mosquito and tick activity in NYC to be at similarly high levels,” M&M Pest Control, a Long Island City-based exterminator, writes on their website.

Warmer temperatures in the south and east could mean earlier emergences of mosquitoes.NOAA

Rainfall in most of the United States is expected to be normal this spring, but potential damp conditions around the Great Lakes and southern Acela Corridor could increase mosquito populations.NOAA

In the South, mosquito populations are “almost all rainfall- and temperature-driven” because snow is not the primary cause of standing water in the region, according to Markowski. While temperatures might not yet be high enough in the region for a major larvae boom, recent storms have authorities “concerned right now in southeast Mississippi, Alabama, Arkansas, Tennessee about mosquito populations,” Markowski said. Not to mention another reason for the South to be on high alert: Culex lactator, a species of mosquito native to South and Central America, has been discovered spreading throughout southwest Florida. Though it hasn’t been extensively studied, we do know Culex is a potential vector for West Nile and St. Louis Encephalitis.

Of especially high concern for infectious disease experts this year will be a place not usually thought of for its mosquitoes: Phoenix’s Maricopa County. Back in 2021, the region experienced the largest single outbreak of West Nile virus in U.S. history, likely due to a wetter-than-average monsoonal season; statewide, 127 people died. This year, winter snowmelt and spring rains have pulled the region out of its drought, but once the floodwaters start to recede, they’ll create major mosquito breeding grounds, NBC’s 12 News reports. The wetter desert environment will also attract more birds — the natural hosts of West Nile virus.

So while there is no guarantee that 2023 is going to be another “monster mosquito season” for the U.S. like 2021, there is no guarantee it won’t be, either. We know the West is unusually wet, which will almost certainly mean more bugs, while the Midwest and East are likewise tracking warm and damp. In the South, where storms are one of the biggest causes of standing water, there are fears that this year’s record number of early-season tornadoes is only a “prelude” of what’s to come.

That makes it all the more important to minimize mosquitoes where we do have some control: “What I try to get people to understand is, just as nature — rainfall, snowfall amounts; temperatures — impact mosquito problems, we have a lot of control over what bites us in our backyards,” Markowski said. “If we’re over-watering our property, or we’re allowing water to stand on our property, you’re making mosquitoes right there that bite you.”

Meanwhile, in New York City, the warmest days of the year so far are expected this week. Short-sleeved, sun-starved urbanites will be out in droves.

As will be mosquitoes.


Sign up to receive the best of Heatmap in your inbox Monday through Friday:

* indicates required
  • Blue

    You’re out of free articles.

    Subscribe today to experience Heatmap’s expert analysis 
of climate change, clean energy, and sustainability.
    To continue reading
    Create a free account or sign in to unlock more free articles.
    or
    Please enter an email address
    By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy
    Climate Tech

    Climate Tech Pivots to Europe

    With policy chaos and disappearing subsidies in the U.S., suddenly the continent is looking like a great place to build.

    A suitcase full of clean energy.
    Heatmap Illustration/Getty Images

    Europe has long outpaced the U.S. in setting ambitious climate targets. Since the late 2000s, EU member states have enacted both a continent-wide carbon pricing scheme as well as legally binding renewable energy goals — measures that have grown increasingly ambitious over time and now extend across most sectors of the economy.

    So of course domestic climate tech companies facing funding and regulatory struggles are now looking to the EU to deploy some of their first projects. “This is about money,” Po Bronson, a managing director at the deep tech venture firm SOSV told me. “This is about lifelines. It’s about where you can build.” Last year, Bronson launched a new Ireland-based fund to support advanced biomanufacturing and decarbonization startups open to co-locating in the country as they scale into the European market. Thus far, the fund has invested in companies working to make emissions-free fertilizers, sustainable aviation fuel, and biofuel for heavy industry.

    Keep reading...Show less
    Green
    AM Briefing

    Belém Begins

    On New York’s gas, Southwest power lines, and a solar bankruptcy

    COP30.
    Heatmap Illustration/Getty Images

    Current conditions: The Philippines is facing yet another deadly cyclone as Super Typhoon Fung-wong makes landfall just days after Typhoon Kalmaegi • Northern Great Lakes states are preparing for as much as six inches of snow • Heavy rainfall is triggering flash floods in Uganda.


    THE TOP FIVE

    1. UN climate talks officially kick off

    The United Nations’ annual climate conference officially started in Belém, Brazil, just a few hours ago. The 30th Conference of the Parties to the UN Framework Convention on Climate Change comes days after the close of the Leaders Summit, which I reported on last week, and takes place against the backdrop of the United States’ withdrawal from the Paris Agreement and a general pullback of worldwide ambitions for decarbonization. It will be the first COP in years to take place without a significant American presence, although more than 100 U.S. officials — including the governor of Wisconsin and the mayor of Phoenix — are traveling to Brazil for the event. But the Trump administration opted against sending a high-level official delegation.

    Keep reading...Show less
    Blue
    Climate Tech

    Quino Raises $10 Million to Build Flow Batteries in India

    The company is betting its unique vanadium-free electrolyte will make it cost-competitive with lithium-ion.

    An Indian flag and a battery.
    Heatmap Illustration/Getty Images

    In a year marked by the rise and fall of battery companies in the U.S., one Bay Area startup thinks it can break through with a twist on a well-established technology: flow batteries. Unlike lithium-ion cells, flow batteries store liquid electrolytes in external tanks. While the system is bulkier and traditionally costlier than lithium-ion, it also offers significantly longer cycle life, the ability for long-duration energy storage, and a virtually impeccable safety profile.

    Now this startup, Quino Energy, says it’s developed an electrolyte chemistry that will allow it to compete with lithium-ion on cost while retaining all the typical benefits of flow batteries. While flow batteries have already achieved relatively widespread adoption in the Chinese market, Quino is looking to India for its initial deployments. Today, the company announced that it’s raised $10 million from the Hyderabad-based sustainable energy company Atri Energy Transitions to demonstrate and scale its tech in the country.

    Keep reading...Show less
    Green