Heat Dome Blanketing Much of US Following Four Hottest Days Ever Observed

Once again this year, a prolonged heat wave is slated to engulf much of the United States. People in the Southwest, Southeast, and Plains could be at particularly high risk of dangerous and possibly deadly heat this week, with the potential for coast-to-coast impacts by mid-August. In western states, already reeling from devastating wildfires, the heat will increase risks of damaging fires and could worsen drought conditions. This comes on the heels of the leading scientific agencies sounding the alarm that this year alone the world has experienced its four hottest days on record and July is on track to be the 14th straight month of record-breaking global temperatures.

More than 57 million people in the United States and its territories are threatened today by what the Union of Concerned Scientists (UCS) has deemed “Danger Season”—the time roughly from May through October in the Northern Hemisphere when climate change impacts in the United States are at their peak and increasingly likely to coincide with one another. Additionally, 60% of extreme heat alerts since May 1, 2024, were made more likely by climate change. This data is according to the UCS Danger Season map, which tracks daily heat, wildfire weather, storm and flood alerts.

Fossil-fuel driven climate change has increased the frequency and severity of extreme-heat events over the last half century. Extreme heat, especially over such an extended period of time, could be harmful for anyone but poses particularly grave risks to those experiencing poverty or homelessness, people (often people of color) living in the hottest parts of urban heat islands, elderly adults, small children, people with cardiovascular and other health conditions, outdoor workers, and people facing electricity shut offs or lacking reliable access to air conditioning. High demand for air conditioning also increases the risk of electricity prices spikes, outages, and increased pollution from fossil fuel-fired power plants. Until the United States and other countries phase out fossil fuels, summers will continue getting hotter and hotter and more dangerous and deadly.

There are actions national, state, and local policymakers can take right now to better protect people. These should include implementing local emergency heat safety plans that entail heat alerts, access to community cooling centers, and other health-protective measures for those most vulnerable to heat. Preventing utility shutoffs during times of extreme weather, including heatwaves like this one, and implementing commonsense safeguards to ensure outdoor workers have access to shade and water, as well as more frequent rest breaks, is also vital. Looking ahead, the U.S. Occupational Safety and Health Administration should expeditiously finalize robust federal heat health safety standards, and the Federal Emergency Management Agency should update their regulations to recognize extreme heat and wildfire smoke as eligible for major disaster declarations.

But ultimately, limiting the number of days of extreme heat in the long term necessitates that policymakers and decisionmakers in all sectors of society do their part to cut heat-trapping emissions, halt the decades-long deception and obstruction by fossil fuel companies that has enabled runaway climate change, phase out fossil fuels, and accelerate the transition to a clean and just energy system.

A list of UCS experts who can discuss this heat dome and other extreme weather events this Danger Season, is available here. They can also discuss the connection of these events to climate change and their impact on the electric grid and other critical infrastructure, as well as relevant local, state, national, and international policies needed to address the climate crisis and accountability for fossil fuel companies whose products are driving this crisis.