UCS Tracking 2025 Climate-fueled “Danger Season.” Map with New Features Now Available Online, Updated Daily.

This month marks the start of “Danger Season”—the time roughly from May through October in the Northern Hemisphere when many climate change impacts are at their peak and increasingly likely to collide with one another. The Union of Concerned Scientists (UCS) has updated and launched its online map to track the places in the United States and its territory of Puerto Rico at risk of extreme heat, storms, flooding, wildfires or poor air quality (a new feature) during the 2025 Danger Season.

The map is updated daily based on data from the U.S. Environmental Protection Agency (EPA), National Weather Service (NWS) and Climate Central. Additionally, it uses population data from the U.S. Census Bureau and data on disadvantaged communities from the Climate and Economic Justice Screening Tool. The UCS Danger Season map also displays the number of people under extreme weather alerts, the percentage of people who have been under at least one extreme weather alert since May 1, the percentage of extreme heat alerts clearly influenced by climate change, and the percentage of people who live in disadvantaged communities under alerts. According to today’s map, more than 42.7 million people in the United States and Puerto Rico are currently facing extreme weather alerts, with 39% of this population living in areas designated as disadvantaged. Additionally, since May 1, 19% of the U.S. population has already experienced at least one extreme weather alert this Danger Season.

The 2025 Danger Season comes during an unrelating assault on lifesaving safeguards and federal agencies by the Trump administration in its first 100 days. This includes cutting staff and funds for vital agencies such as the National Oceanic and Atmospheric Administration (NOAA), Federal Emergency Management Agency (FEMA) and EPA; pulling the United States out of the landmark Paris climate agreement; attacking key Clean Air Act pollution standards; disbanding the author team for the quadrennial National Climate Assessment; denying states’ disaster aid requests and more. The president’s proposed budget released last week doubles down on these harmful funding cuts to essential agencies while boosting giveaways to polluters and billionaires. These actions do not alter the scientific facts and will instead leave the United States at risk of flying blind into a world made more perilous by human-caused climate change, especially during Danger Season. At the same time people across the country find themselves at risk of greater health and economic harms from worsening climate and extreme weather events, the fossil fuel industry and their allies are expected to see continued oil and gas profits.

According to a new blogpost titled “Four Ways the Trump Administration is Making Danger Season Worse This Year” by Dr. Juan Declet-Barreto, a senior social scientist for climate vulnerability at UCS, many NWS Meteorologists in Charge (MIC) positions across the country are currently vacant, which could undermine lifesaving weather forecasts and services. As of early May, 30 out of 122 Weather Forecasting Offices did not have MICs on staff due to the ongoing attacks on NOAA. This leaves 78 million people in 796 counties—or 23% of the U.S. population—without experienced MIC leadership.

Last year was the hottest on record globally, adding to a long-term trend: The last 11 years have been the 11 hottest on record. Also in 2024, at least 568 lives were lost in 27 separate U.S. extreme weather and climate disasters that each reported damages of $1 billion or more with a total economic cost of at least $182.7 billion. This Danger Season is again expected to be severe. NOAA’s three-month seasonal outlooks are forecasting above average temperatures for large swaths of the country. Additionally, the forecast for the upcoming wildfire season, which has already had a catastrophic and early start, shows above average wildfire risk—especially for the western United States, Florida and Texas—in the months ahead. Finally, early forecasts are predicting an above average Atlantic hurricane season.

UCS experts are available to discuss the anticipated U.S. and global extreme weather; connection between extreme weather events and fossil fuel-induced climate change; impact of extreme weather on the electric grid, critical infrastructure, agriculture, affordable housing, insurance market, outdoor workers, and vulnerable populations; Trump administration actions and their effect on weather and climate forecasting, federal disaster response, and local recovery efforts; building equitable climate resilience; relevant local, state, national, and international best practices and policies needed to address the climate crisis and transition to clean energy; and holding fossil fuel companies accountable including through litigation, regulation and legislation.

Below is a list of UCS experts who can discuss the 2025 Danger Season:

• Dr. Marc Alessi, a climate attribution science fellow at UCS. He is based in Syracuse, New York. Click here to view his biography.
• Paul Arbaje, an energy analyst at UCS. He is based in New York City, New York. Click here to view his biography.
• Dr. Astrid Caldas, a senior climate scientist for community resilience at UCS. She is based in Washington, D.C. and is fluent in English and Portuguese. Click here to view her biography.
• Dr. Juliet Christian-Smith, the western states program director at UCS. She is based in Berkeley, California. Click here to view her biography.
• Dr. Rachel Cleetus, the policy director for the Climate and Energy Program at UCS. She is based in Cambridge, Massachusetts. Click here to view her biography.
• Dr. Juan Declet-Barreto, a senior social scientist for climate vulnerability at UCS. He is based in Washington, D.C. and is fluent in English and Spanish. Click here to view his biography.
• Dr. Amanda Fencl, the director of climate science at UCS. She is based in Oakland, California. Click here to view their biography.
• Dr. Angel Fernández-Bou, a bilingual senior climate scientist at UCS. He is based in Merced, California and is fluent in English and Spanish. Click here to view his biography.
• Dr. Omanjana Goswami, a scientist with the Food and Environment Program at UCS. She is based in Washington, D.C. Click here to view her biography.
• Mike Jacobs, a senior manager for the energy campaign at UCS. He is based in Boston, Massachusetts. Click here to view his biography.
• Dr. Ed Lyman, the director of nuclear power safety at UCS. He is based in Washington, D.C. Click here to view his biography.
• Dr. Delta Merner, the associate director of the Science Hub for Climate Litigation at UCS. She is based in Baltimore, Maryland. Click here to view her biography.
• Zoe Middleton, the associate policy director of just climate resilience at UCS. She is based in Houston, Texas. Click here to view her biography.
• Kathy Mulvey, the accountability campaign director for the Climate and Energy Program at UCS. She is based in Cambridge, Massachusetts. Click here to view her biography.
• Dr. Carly Phillips, a scientist with the Science Hub for Climate Litigation at UCS. She is based in Cambridge, Massachusetts. Click here to view her biography.
• John Rogers, the associate director of energy analytics at UCS. He is based in Cambridge, Massachusetts, and is fluent in English and Spanish. Click here to view his biography.
• Erika Spanger, the director of climate analytics at UCS. She is based in Cambridge, Massachusetts. Click here to view her biography.
• Shana Udvardy, a senior climate resilience policy analyst at UCS. She is based in Washington, D.C. Click here to view her biography.
• Dr. Stacy Woods, the research director for the Food and Environment Program at UCS. She is based in Washington, D.C. Click here to view her biography.

Contact UCS Climate and Energy Media Manager Ashley Siefert Nunes to speak with a UCS scientist or analyst on the 2025 Danger Season or other related topics.

Additional UCS Resources and Analyses:

• UCS blogposts from this and previous Danger Seasons are available here.
• A peer-reviewed study by UCS titled “The Fossil Fuels Behind Forest Fires: Quantifying the Contribution of Major Carbon Producers to Increasing Wildfire Risk.”
• A peer-reviewed study by UCS titled “Too Hot to Work: Assessing the Threats Climate Change Poses to Outdoor Workers.” For the interactive mapping tool, click here.
• A peer-reviewed study by UCS titled “Killer Heat: Climate Choices and the Future of Dangerously Hot Days.” To get the results for a specific city or county, use the online widget. For the interactive mapping tool, click here.
• A UCS report titled “U.S. Military on the Frontlines of Extreme Heat.”
• A UCS report titled “Farmworkers at Risk: The Growing Dangers of Pesticides and Heat.”