Heat dome to deliver extreme temperatures, high wildfire risk to West
Dangerous heat will expand across California and the Southwest as a heat dome settles over the West, sending highs well above the historical average and increasing wildfire danger.
A heat dome is an area of high pressure high in the atmosphere that strengthens and becomes stagnant. RealFeel® Temperatures can climb well into the triple digits in a heat dome.
The large dome of high pressure bringing dangerous temperatures to central portions of the Plains this week will shift west by late week. As this occurs, temperatures are expected to climb well above the historical average across much of the Southwest and interior California, with many locations forecast to reach their highest temperatures of the year so far.
By Friday, the heat dome is expected to be centered over Utah, allowing excessive heat to expand across much of the Southwest and interior California. The heat dome could center even farther southwest for a time in early August.
"Given the forecast position of the high pressure area associated with the expansive heat dome in the West, there could be enough easterly breezes to bring intense heat to the Los Angeles basin next weekend with highs well into the 90s F possible," AccuWeather Senior Meteorologist Alex Sosnowski said.
Historical average high temperatures for the Los Angeles area are in the lower 80s, so that temperatures could run roughly 10-15 degrees higher. Sosnowski said that while downtown Los Angeles had extreme heat during the March 2026 heat wave, this event could push temperatures a few degrees higher.
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Farther east across the Desert Southwest, highs are expected to peak between 110 and 120 degrees by next weekend. With exceptionally high overnight lows, there will be an increased risk of heat-related illnesses, as the body has little opportunity to recover from daytime heat.
"Phoenix, Las Vegas and Palm Springs, California, for example, could experience their highest temperatures of the year so far," Sosnowski added. "During periods of extreme heat and less-dense air, the airline industry may closely scrutinize baggage weight as a longer takeoff distance is needed."
Thunderstorms produced by the North American monsoon are expected to become less widespread as the heat dome strengthens over the region. Despite fewer storms, any dry lightning strikes combined with very high temperatures and dry vegetation could increase wildfire risk into the weekend, even for areas farther north and away from the core of the heat. This would come just days after thousands of lightning strikes sparked several wildfires in Oregon alone.
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