The West’s record-breaking heat wave is not over, as the heat dome shifts to the Plateau
An oppressive heat wave across much of the western United States left cities and their residents reeling from conditions this weekend that are more common at the height of summer.
The explosive heat wave, which has been ongoing for a week in California and the desert Southwest, will continue to build and spread eastward across the US in the coming days. Temperatures 20 to 40 degrees Fahrenheit above average for this time of year will be common from the Southwest to the Great Plains, according to the National Weather Service.
More than 150 daily heat records and nearly 50 all-time monthly records have already been broken since Tuesday, the weather service said, with more expected to fall this weekend and in the coming days.
Parts of California were well above seasonal averages heading into the weekend, with Death Valley reaching 105 degrees on Thursday, a new monthly record. Highs are expected to remain in the triple digits next week, according to the National Weather Service.
Southern Nevada was also experiencing summer-like conditions this weekend. Las Vegas hit 96 degrees on Saturday and is expected to reach 93 degrees on Sunday. More than 40 night cooling stations were opened across the city to help people cope with the heat.
“Although Southern Nevada is used to very hot weather, we are experiencing an unprecedented heat wave months before the summer season,” Clark County Commissioner Marilyn Kirkpatrick said Wednesday in a statement. “Our bodies are not used to these temperatures, and that puts people at greater risk of heat-related illnesses.”
The Las Vegas office of the National Weather Service urged people to take appropriate precautions to avoid heat-related illness.
“If you spend time outside, remember to wear sunscreen, eat light meals, and avoid caffeine and alcohol,” the weather service said in X.
In Colorado, Fort Collins hit a record high of 91 degrees Saturday, the highest March temperature since the city’s record-keeping began in 1893. The 91-degree high also surpassed the hottest April temperature in Fort Collins by 2 degrees, according to the National Weather Service.
“The city has not recorded a March high above 81F before 2026,” the Boulder office of the NWS said Sunday at X.
Denver, meanwhile, hit 86 degrees on Saturday, setting a new record for the month of March. The heat, low humidity and windy winds in Colorado are increasing the risk of wildfires across the state.
This week’s heat record was created by a heat dome, a stubborn high-pressure system that has trapped hot air over much of the western US like a lid on a pot.
It can be challenging to pin down the actual impact of climate change on specific extreme weather events, but global warming is known to make heat waves more frequent, more intense and longer lasting.
A new report from the World Weather Attribution Group, which analyzes the impact of climate change on extreme events, said on Friday that the March heat wave “would not have happened without human-caused climate change.”
In Phoenix, where temperatures reached 105 degrees on Friday and Saturday — a record for the entire month of March — several popular hiking trails were closed during daylight hours. The shutdown happened months before these types of heat protection measures went into effect.
The Phoenix Trail Heat Safety Program, established in 2021, restricts access to trails in and around the city when National Weather Service extreme heat warnings are in effect. This weekend, trails in Camelback Mountain Preserve, Phoenix Mountains Preserve and South Mountain Park and Preserve will be closed from 8 a.m. to 5 p.m. local time.
An extreme heat warning remains in effect for the region until Sunday. The Maricopa County Public Health Department, which includes Phoenix, told people to stay indoors as much as possible in the coming days.
“Remember to drink your water, limit outdoor activities during high temperatures, and check on your loved ones who are at risk,” public health officials wrote in a Facebook post.
Dozens of outdoor events in the Phoenix area had to make changes due to the extreme heat. At least 10 Major League baseball spring training games, for example, moved their start times from noon to after 6 p.m. to avoid the worst triple-digit temperatures, the Cactus League said in a statement.
In Glendale, Arizona, the local fire department said it transported about 30 people to local hospitals Saturday for heat-related illnesses during the Luke Days Air Show.
“In addition to those transports, Glendale Fire Department personnel, along with our public safety partners, evaluated and treated a number of others at the scene who had burn-related symptoms,” a fire department spokesperson told NBC News via email.
The National Weather Service said temperatures on Sunday are expected to be in the 90s and 100s across the Southwest and in the 80s in parts of Utah, Idaho, Wyoming, Colorado and New Mexico. Across the Great Plains, meanwhile, highs will range from the 70s to the 90s.
