Early-season heat spreads to central US, raising health and wildfire risks, AccuWeather says

Dangerous early-season heat is gripping parts of the West and will expand into the central U.S. throughout this week, bringing highs in the 90s and 100s to new areas, according to AccuWeather. Experts explained that the summerlike weather is expected to arrive earlier than the historical average across much of the South, central U.S.. and West.

Cities in the western U.S. like Las Vegas and Fresno are already seeing triple-digit temperatures, before the surge of heat moves east into the Plains, AccuWeather experts said.

"This early-season heat is on the move after baking the Southwest. The warmth is expected to surge into the Plains later this week, bringing highs in the 90s and even 100 degrees to new areas," AccuWeather Meteorlogist Elizabeth Danco explained. "For millions of people, it will feel like summer arriving all at once."

Experts said this surge of heat moving west could bring potential issues, such as health risks, higher energy demand, and possible fire danger. The persistent stretches of above-average temperatures, combined with warmer, more humid nights in some areas, can increase the risk of heat-related illness and drive up cooling demand and power bills, according to AccuWeather experts.

"This level of summerlike heat in mid-May can lead to a range of issues, from heat-related illnesses and increased energy demand to a heightened risk of wildfires," Danco said. "Heat, low humidity, gusty winds and the potential for storms with lightning will overlap across parts of the West, increasing the risk of wildfires igniting and spreading rapidly."

A quickly developing El Niño is also expected to help shape the summer pattern by influencing the tropics, according to AccuWeather, which could potentially contribute to a divide between wetter areas in the middle of the country and hotter, drier zones farther west and south.

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AccuWeather long-range experts said there is currently a 15% to 20% chance of a Super El Niño developing before the end of 2026.