A severe heatwave has engulfed much of the western United States this weekend, plunging cities and residents into sweltering conditions typically reserved for mid-summer.

An unrelenting heat wave has gripped California and the desert Southwest, with temperatures expected to soar 20 to 40 degrees Fahrenheit above the seasonal average. This heat will spread eastward into the central United States in the coming days, as reported by the National Weather Service.

Since Tuesday, over 150 daily temperature records and nearly 50 monthly high records have been shattered. The weather bureau indicates that temperatures could climb even higher this weekend.

California has seen significant rises in temperatures as it heads into the weekend, with Death Valley hitting a record monthly high of 105 degrees on Thursday. Projections show that triple-digit highs will persist into next week, according to the National Weather Service.

Southern Nevada has also been experiencing summer-like conditions. Las Vegas recorded 96 degrees on Saturday and is forecasted to reach 93 degrees on Sunday. In response, more than 40 cooling stations have opened across the city to assist residents in coping with the extreme heat.

“Southern Nevada is accustomed to extreme heat, but we’re facing an unprecedented heat wave months before summer,” stated Clark County Commissioner Marilyn Kirkpatrick. The statement emphasizes that residents are not yet acclimated to such high temperatures, raising the risk of heat-related illnesses.

The Las Vegas branch of the National Weather Service is advising individuals to take necessary precautions to prevent heatstroke.

“When outdoors, remember to use sunscreen, consume light snacks, and steer clear of caffeine and alcohol,” the Bureau of Meteorology advised in a tweet.

Fort Collins, Colorado, reached a remarkable 91 degrees on Saturday, marking its highest March temperature since record-keeping began in 1893. This peak was two degrees higher than the historical April high in Fort Collins, as highlighted by the National Weather Service.

“Before 2026, the city hadn’t recorded a March high exceeding 81 degrees Fahrenheit,” stated the NWS Boulder office on X.

Denver also hit a new March record, reaching 86 degrees on Saturday. This extreme heat, combined with low humidity and strong winds, heightens the risk of wildfires across Colorado.

This week’s historic heat wave is attributed to a heat dome, a persistent ridge of high pressure that traps hot air over large areas in the western U.S., akin to a lid on a pot.

While it’s challenging to directly link specific extreme weather events to climate change, evidence shows that global warming is increasing the frequency, intensity, and duration of heat waves.

A recent report by the World Weather Attribution group indicates that this March’s heatwave “would have been virtually impossible without anthropogenic climate change.”

Numerous popular hiking trails in Phoenix were closed due to temperatures reaching 105 degrees on Friday and Saturday, setting a record for March. These closures were initiated earlier than usual to protect public safety.

The Phoenix Trail Thermal Safety Program, established in 2021, restricts access to local trails when a National Weather Service heat warning is active. This weekend, safeguards will be enforced at Camelback Mountain Preserve, Phoenix Mountain Preserve, and South Mountain Park and Preserve from 8 a.m. to 5 p.m.

A heat warning remains in effect for the region until Sunday. The Maricopa County Public Health Department advises residents to stay indoors in air-conditioned spaces throughout the extreme heat event.

“Stay hydrated, limit outdoor activities during peak heat, and check on vulnerable friends and family,” public health officials recommended in a Facebook post.

Outdoor events in the Phoenix area have been adjusted due to the heat. For instance, at least 10 Major League Baseball spring training games have rescheduled their start times to after 6 p.m. local time in order to avoid the extreme afternoon temperatures typical of the Cactus League announced in a statement.

The Glendale fire department reported that approximately 30 individuals were transported to nearby hospitals for heat-related issues during the Luke Days Air Show.

“Aside from these transports, our personnel attended to many others on-site suffering from heat-related symptoms,” a spokesperson from the Glendale Fire Department communicated to NBC News via email.

On Sunday, temperatures across the Southwest will hover between the 90s and 100 degrees, with the 80s expected in parts of Utah, Idaho, Wyoming, Colorado, and New Mexico. The Great Plains will experience highs ranging from the 70s to the 90s, according to the National Weather Service.