Communities across the Western United States are in for another week of unusually high temperatures amid an ongoing and historic early-season heat wave. It has broken March temperature records in nearly 180 cities, including Phoenix, which hit 105 degrees Fahrenheit last Thursday.
The National Weather Service forecasts more than 200 record-high temperatures this week, as the heat wave blankets portions of California, the Southwest, the central Great Basin, the central/southern Plains and mid-lower Mississippi Valley. A new rapid attribution study found the weather event would have been “virtually impossible without climate change.”
I know I sound like a broken record talking about records breaking. But the anomalous weather poses profound risks to snowpack and water availability out West, which experts warn could be critically low this spring. Meanwhile, copious rain in Hawaii is triggering widespread flooding, crop losses and damage throughout the islands.
Western Heat Wave’s Climate Connection
The Western heat wave was largely caused by a high-pressure system trapping heat from unusually warm Pacific Ocean waters, bringing temperatures 25 to 35 degrees Fahrenheit higher than normal in some areas.
A study published Friday by the research group World Weather Attribution found that human-caused climate change has made this kind of heat wave about four times more likely to occur over the last decade.
The researchers used weather records, forecasts and climate models to compare how these types of heat waves changed under the current rate of global warming, 1.3 degrees since pre-industrial times. They noted the affected Western region is warming much faster than many other parts of the world.
“These findings leave no room for doubt. Climate change is pushing weather into extremes that would have been unthinkable in a preindustrial world,” co-author Friederike Otto, a climate science professor at Imperial College London, said in a statement.
The study points out that heat waves outside the “traditional summer period” heighten health risks: People are not yet acclimatized and seasonal response measures, such as cooling centers, may not be fully operational. Rachel White, an atmospheric scientist at the University of British Columbia who was not involved in the study, told Eos that more extensive analysis will be needed to determine climate change’s influence with greater certainty.
“To do this study as quickly as possible, they are using the one dataset that does include data for very recent days, but the way that it does that is by including forecast data,” she said in an email to Eos. “This is a reasonable thing to do if you need to do a study this quickly (and this is a rapid attribution!), but does come with the caveat that the exact numbers they are reporting in terms of return period etc. will likely change as we are able to more carefully analyse observational data.”
More broadly, the heat wave jeopardizes water availability out West following a winter with unsettlingly low snowpack levels in many states, particularly in the snow-fed Colorado River Basin.
Water managers depend on the slow melt of snowpack to supply water to streams, rivers and reservoirs for irrigation, recreation and drinking water. As I reported earlier this month, high temperatures can cause this limited snowpack to melt and evaporate more quickly. The Colorado Climate Center at Colorado State University reported that the heat took a “major toll” on the state’s snowpack, which sits at 44 percent of average levels.
Relentless Storms Soak Hawaii
As the West Coast bakes, communities in Hawaii are struggling against the state’s worst flooding in more than two decades. Starting in mid-March, low-pressure systems known as Kona lows have fueled intense, windy and exceptionally wet storms over the islands, with only brief reprieves in between. The storms caused widespread flooding across Oʻahu, which damaged structures, swept cars onto the street and knocked out power for many locals, Honolulu Civil Beat reports.
“We’ve been here almost 20 years. … We lost everything,” Oʻahu resident Melanie Lee told CBS News. “My children’s pictures. Just real sentimental stuff. Now it’s like, now where we go from here?”
Locals and officials were especially worried that the immense rainfall would overwhelm an aging dam on the Wahiawa Reservoir in northern Oʻahu as water rose to a record 85.1 feet—just five feet shy of what the dam could handle. The structure held, but long-term concerns remain over the dam’s ability to handle water flows from worsening storms, experts say.
Rain also hammered parts of Lahaina, particularly susceptible to flooding due to burn scars from the devastating fires that tore through Maui in 2023. As I reported last summer, wildfires can burn so hot that they cause shifts in soil that make the ground fairly water-repellent, making flooding more dangerous.
Gov. Josh Green estimated on Friday that the storms had already caused around $1 billion in damage. And more flooding hit over the weekend. Farmers reported nearly $11 million in losses across the North Shore of Oʻahu, Maui, Molokaʻi and the Big Island, Honolulu Civil Beat reports.
On Monday, Green said he formally requested that President Donald Trump issue a major disaster declaration, which could unlock more resources for recovery. In the meantime, state and local governments have launched relief efforts, and community members are digging their way through mud and debris to return home after evacuating last week.
“The strength of Hawaii is our people,” Green said at a Monday press conference. “Throughout this storm, we saw neighbors helping neighbors, communities stepping up and our emergency teams working tirelessly to keep everyone safe.”
More Top Climate News
A new analysis by Grist breaks down how insurance rates are changing by state in the face of global warming and other factors. Nearly every state is seeing rising costs, with the nationwide average bill rising 12 percent last year to $2,948, data from insurance price comparison firm Insurify showed. Florida takes the cake as the most expensive place to insure a home, which matches my colleagues’ extensive reporting on the subject in the state.
Washington State University engineered a new type of apple that researchers think will better withstand rising costs and fluctuating weather, Anna Griffin reports for The New York Times. Apples in the U.S. can be difficult to grow under certain climate conditions—and difficult to sell, with high competition in the market from other countries. The university used plant-breeding techniques to create a new variety known as the Sunflare. The fruit likely won’t hit consumer shelves until 2029.
The Trump administration announced it will reimburse the French company TotalEnergies $1 billion to drop its two U.S. offshore wind leases, Amy Harder reports for Axios. The cancellation tracks with President Donald Trump’s concerted attacks on the wind industry, which I reported on in August. TotalEnergies CEO Patrick Pouyanné said the company’s decision to accept this agreement does not mean it will renounce offshore wind in locations outside the U.S.
Postcard From … Japan
This week’s installment of “Postcards From” is courtesy of ICN Mountain West reporter Jake Bolster, who recently visited Japan on vacation.
“These pictures were taken in Asakusa, surrounded by both Buddhist and Shinto temples in the heart of Old Tokyo,” he said. “Though Japan’s cherry blossom season typically doesn’t begin until late March, this tree and others in the area appeared in full bloom.”
Today’s Climate readers, what are you most excited to do as the seasons change? Any fun memories to share from last year that you are looking forward to recreating? We want to feature your photos from nature, whether you are in a city, suburb, forest or anywhere in between. Please send your photos to [email protected].
About This Story
Perhaps you noticed: This story, like all the news we publish, is free to read. That’s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. We make our news on climate and the environment freely available to you and anyone who wants it.
That’s not all. We also share our news for free with scores of other media organizations around the country. Many of them can’t afford to do environmental journalism of their own. We’ve built bureaus from coast to coast to report local stories, collaborate with local newsrooms and co-publish articles so that this vital work is shared as widely as possible.
Two of us launched ICN in 2007. Six years later we earned a Pulitzer Prize for National Reporting, and now we run the oldest and largest dedicated climate newsroom in the nation. We tell the story in all its complexity. We hold polluters accountable. We expose environmental injustice. We debunk misinformation. We scrutinize solutions and inspire action.
Donations from readers like you fund every aspect of what we do. If you don’t already, will you support our ongoing work, our reporting on the biggest crisis facing our planet, and help us reach even more readers in more places?
Please take a moment to make a tax-deductible donation. Every one of them makes a difference.
Thank you,
Kiley Price
Reporter
Kiley Price is a reporter at Inside Climate News, with a particular interest in wildlife, ocean health, food systems and climate change. She writes ICN’s “Today’s Climate” newsletter, which covers the most pressing environmental news each week.
She earned her master’s degree in science journalism at New York University, and her bachelor’s degree in biology at Wake Forest University. Her work has appeared in National Geographic, Time, Scientific American and more. She is a former Pulitzer Reporting Fellow, during which she spent a month in Thailand covering the intersection between Buddhism and the country’s environmental movement.
