Danger Season 2024: It’s Already Started

May 23, 2024 | 2:40 pm
Construction worker Felipe Campuzano pours water on his face to cool off as he digs a sanitation pipe ditch during a heatwave on August 4, 2022 in Philadelphia, Pennsylvania.Mark Makela/Getty Images
Erika Spanger-Siegfried
Director of Strategic Climate Analytics

Editor’s note: Updated to clarify seasonal periods and add links.

Ahead of Memorial Day, the unofficial kick-off of summer, we are back with an annual warning that gets more pointed each year: it is now Danger Season 2024, and everyone needs to be ready. Because the hits are coming, and they’re going to hurt.

“Danger Season” refers to the warmer months when, turbo-charged by climate change, extreme events like heat waves, heavy rainfall, wildfires, and poor air quality bring miserable and often dangerous, conditions. You already know you’re not experiencing the summers of your youth (given the accelerating pace of climate change, this applies to almost anyone who can read this post). It’s important to know, also, that climate change isn’t going to unfold for us in barely perceptible increases in temperature, upticks on a graph we can scan in the morning news. It’s going to crash into our lives in the form of damaging, even devastating, extreme events, particularly in Danger Season.

Here at UCS, we’re tracking Danger Season impacts on a daily basis with this interactive tool, capturing and communicating the climate change connections, highlighting harm to vulnerable people, and talking about what we can do to prepare, to build equitable resilience, and to slow down this runaway climate train with a fast, fair phaseout of fossil fuels and accountability for the fossil fuel companies whose deception and delay tactics played a huge role in getting us into this mess—and who continue to profit as people suffer.

What happened to summer?

Summers–and all the seasons–happen because of Earth’s tilt on its axis as it orbits the sun. With this tilt, the Northern Hemisphere will face more directly toward the sun during the months surrounding the June solstice, causing us to experience summer, while the Southern Hemisphere experiences the opposite seasonality. “Danger Season” follows that more direct gaze of the sun. With fossil-fuel pollution trapping heat and driving up global average temperatures, those warmer months are warmer than ever. And, in human history, I do mean ever. Higher ocean and air temperatures manifest in storms, heat, precipitation, drought and wildfires that can be more intense, more frequent, and/or longer lasting.

This NASA graphic captures how climate change affects the extreme weather that tends to play out in Danger Season. Watch the full animation here: https://science.nasa.gov/wp-content/uploads/2023/11/ExtremeEventsGraphic.mp4

Wherever one lives in the U.S., these trends are inescapable. Whether we’re under the orange skies millions experienced last summer amidst smoke from Canadian wildfires or evacuation orders from those same fires, whether unnerving or downright traumatizing, climate change is making its presence known, and these warm months—Danger Season—are its main stage.

Now, is every extreme weather event we experience made worse by climate change? No. But we know that climate change has made many disasters more frequent and more severe. Scientific analysis, called “event attribution,” can help quantify whether and how the fingerprint of climate change impacted a particular event, and these analyses are often available in rapid response formats following a disaster.

What’s happening with this summer?

Any sense that climate change would unfold gradually was laid to rest in 2023 when so many significant climate records were shattered by previously unthinkable margins. The first few months of 2024 have seen the continued march of record global heat conditions. April marked the 11th hottest month on record.

Source: https://climate.copernicus.eu/copernicus-global-temperature-record-streak-continues-april-2024-was-hottest-record

Average ocean temperatures have also been at record levels since May of 2023.

Source: https://climatereanalyzer.org/clim/t2_daily/?dm_id=world

This heat was enabled in part by the fact that we were in the El Niño phase of the so called El Niño Southern Oscillation inter-annual climate cycle. El Niño typically drives higher global average temperatures. Here in 2024, we are seeing the transition from El Niño to a neutral phase, and we can likely expect a shift to La Niña to happen late this summer. Given that global average ocean temperatures remain at record high levels, and air temperatures continue to break records, there’s uncertainty about how summer 2024 will play out. But here’s what NOAA, our federal climate agency, is currently forecasting.

  • Widespread above-normal heat

The forecast for July through September is for above-normal heat conditions from coast to coast, with highest heat risk in parts of the country—like the Southwest and Texas—that weathered unprecedented heat last year.

Source: https://www.cpc.ncep.noaa.gov/products/predictions/long_range/seasonal.php?lead=3
  • A hectic hurricane season

Just this morning, NOAA released its Atlantic hurricane season outlook, anticipating an above-normal and possibly record-breaking season. The North Atlantic remains incredibly hot, and hot water is a hurricane’s source of fuel. With the official start of hurricane season next week, we’re entering a “hope for the best, prepare for the worst” situation.

Source: https://www.noaa.gov/news-release/noaa-predicts-above-normal-2024-atlantic-hurricane-season
  • Precipitation and drought forecast

An updated drought forecast will be released next week, but at this time, drought persistence and development are forecast for large areas of the Northwest, Southwest and South Central U.S.

Source: https://www.drought.gov/data-maps-tools/us-seasonal-drought-outlook

It is worth noting that the drought conditions our northern and southern neighbors are facing are currently far more severe, with much of Mexico facing severe, extreme, or exceptional drought.

  • Wildfire forecast

Atmospheric rivers doused California with such exceptional rainfall earlier this year that the threat of wildfire there has for now been greatly tamped down (though this also spurred the growth of vegetation that will fuel future fires). The persistent dry conditions in Canada, unfortunately, point to an active wildfire season there, with potentially harmful air quality impacts for Canadian territories and U.S. states downwind. And Hawaii, still reeling and recovering from last year’s devastating wildfires, faces another season of wildfire risk.

Source: https://www.nifc.gov/nicc-files/predictive/outlooks/NA_Outlook.pdf

What we’re already seeing on the ground

It’s the third week in May, and already we’re seeing extremes that alarm us in their magnitude and hurt like hell on the ground.

Canadian wildfires are once again burning and compromising air quality in the Midwest.

A prolonged heat wave has beset a large swath of the Southeast. In Florida, Key West was shocked with 115 degree Fahrenheit heat index conditions last week, tying the all-time record high temperature in the middle of May.

Source: https://x.com/BMcNoldy/status/1790880195609547084

Much of Puerto Rico has endured heat index conditions well over 100 degrees. And Texas… whew.

The derecho that slammed down in Texas earlier this week has left the Houston area reeling and the recovery situation is being made much worse by early-season extreme heat, an outbreak of mosquitoes, some of which are testing positive for West Nile Virus, and power outages which, though largely addressed, left hundreds of thousands of people without electricity and air conditioning over a miserable several days.

The connection to climate change remains less clear for some extreme weather events, like derechos, than others, such as extreme heat. But the concentration of these extremes during our warmer months means heightened summer risk for which we need to be better prepared.

The official start of summer may be a month away, but Danger Season has begun.

What’s next?

As outlined above, the forecasts are coming into better focus. Inevitably, it promises to be a dangerous season. And given the enduring inequity and legacy of racism across the nation, it promises to harm marginalized and historically disadvantaged people most. Tune in soon for my colleague Juan Declet-Barreto’s take on the outlook for inequitable harm as the season’s impacts unfold.

We’ll be tracking the 2024 Danger Season in our daily-updated web feature, and with quick-breaking analyses focused on issues of racial equity. We’ll be flagging fossil fuel accountability for climate harm. And we’ll be calling for more ambitious climate action on both heat-trapping emissions reductions (e.g., the clean energy transition and a modernized grid) and adaptation (e.g., just and climate-informed preparedness and recovery efforts in the wake of inevitable disasters).

Follow us on social media for rapid response updates as situations unfold.

Stay tuned, prepare now, and let’s try to stay safe.