Records shattered as summer heat hits Southwest in March; 'This is what climate change looks like'

“This is what climate change looks like in real time: extremes pushing beyond the bounds we once thought possible,” said University of Victoria climate scientist Andrew Weaver. “What used to be unprecedented events are now recurring features of a warming world.”

March's heat would have been virtually impossible without human-caused climate change, according to a report Friday by World Weather Attribution, an international group of scientists who study the causes of extreme weather events.

More than a dozen scientists, meteorologists and disaster experts queried by The Associated Press put the March heat wave in a kind of ultra-extreme classification with such events as the 2021 Pacific Northwest heat wave, the 2022 Pakistan floods and killer hurricanes Helene, Harvey and Sandy.

The area of the U.S. being hit by extreme weather in the past five years has doubled from 20 years ago, according to the National Oceanic and Atmospheric Administration's Climate Extremes Index, which includes various types of wild weather, such as heat and cold waves, downpours and drought.

The United States is breaking 77% more hot weather records now than in the 1970s and 19% more than the 2010s, according to an AP analysis of NOAA records. In the United States, the number and average cost of inflation-adjusted billion-dollar weather disasters in the last couple years is twice as high as just 10 years ago and nearly four times higher than 30 years ago, according to records kept by NOAA and Climate Central, a nonprofit group of scientists and communicators who research and report on climate change.

Trying to keep up with extremes and failing

“It’s really hard to even keep up with how extreme our extremes are becoming,” said Climate Central Chief Meteorologist Bernadette Woods Placky. “It’s changing our risk, it’s change our relationship with weather, it’s putting more people in risky situations and at times we’re not used to. So yes, we are pushing extremes to new levels across all different types of weather.”

For government officials who have to deal with disaster it's been a huge problem.

Craig Fugate, who directed the Federal Emergency Management Agency until 2017, said he saw extremes increasing.

“We were operating outside the historical playbook more and more. Flood maps, surge models, heat records — events kept showing up outside the envelope we built systems around. That’s just what we saw,” Fugate said via email.

He added: “We built communities on about 100 years of past weather and assumed that was a good guide going forward. That assumption is starting to break. And the clearest signal isn’t the science debate. It’s insurers walking away.”

‘Virtually impossible’ without climate change

Climate scientists at World Weather Attribution did a flash analysis — which is not peer-reviewed yet — of whether climate change was a factor in this Southwest heat wave. They compared this week's expected temperatures to what's been observed in the area in March since 1900 and computer models of a world with climate change. They found that “events as warm as in March 2026 would have been virtually impossible without human-induced climate change.”

That warming, from the burning of coal, oil and natural gas, added between 4.7 degrees to 7.2 degrees F (2.6 to 4 degrees C) to the temperatures being felt, the report found.

“What we can very confidently say is that human-caused warming has increased the temperatures that we’re seeing as a result of this heat dome, and it’s going to be pushing those temperatures from what would have been very uncomfortable into potentially dangerous,” said report co-author Clair Barnes, an Imperial College of London attribution scientist.

Examples abound of high heat and extreme weather

The Southwest heat wave is solidly in the category of “giant events,” with temperatures up to 30 degrees Fahrenheit (16.7 degrees Celsius) above normal, said Stanford University climate scientist Chris Field.

He listed five others in the last six years: a 2020 Siberia heat wave, the 2021 Pacific Northwest heat wave that had British Columbia warmer than Death Valley, the summer of 2022 in North America, China and Europe, a 2023 western Mediterranean heat wave and a 2023 South Asian heat wave with high humidity.

And that doesn't include the East Antarctica heat wave of 2022 when temperatures were 81 degrees (45 degrees Celsius) warmer than normal. That's the biggest anomaly recorded, said weather historian Chris Burt, author of the book “Extreme Weather.”

Worsening wild weather influenced by climate change isn't just superhot days, but includes deadly hurricanes, droughts and downpours, scientists told AP.

Devastating floods hit West Africa in 2022 and again in 2024. Iran is in the midst of a six-year drought. And the deadly Typhoon Haiyan hitting the Philippines in 2013 shocked the world.

Superstorm Sandy, which in 2012 flooded New York City and neighbors, had tropical storm-force winds that covered an area nearly one-fifth the area of the contiguous United States. It spawned 12-foot seas over 1.4 million square miles, about half the size of the U.S., with energy equivalent to five Hiroshima-sized atomic bombs, said Yale Climate Connections meteorologist Jeff Masters.

And don't forget wildfires that are worsened by heat and drought, so recent extremes should include 2025's Palisades and Eaton wildfires, which were the costliest weather disaster in the United States last year, said Climate Central meteorologist and economist Adam Smith.

“This is due to climate change, that we see more extreme events, and more intense ones and have so many records being broken,” said Friederike Otto, an Imperial College of London climate scientist who coordinates World Weather Attribution.

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