San Francisco’s unusual warmth arrived with a rare heat wave that has been baking much of the U.S. West into late March, the Associated Press reported Tuesday. The city, better known for chilly summers and frequent fog and drizzle, saw residents pack Crissy Field’s shoreline and take advantage of sunshine as temperatures approached local record levels for the month.
The Bay Area’s warmth was driven by forecasts suggesting nearly 90-degree Fahrenheit highs, while farther east in the desert Southwest, forecasters warned that temperatures approaching or exceeding triple digits could arrive weeks earlier than normal. The AP report said Phoenix was expected to top 100 F (37.7 C) this week, a benchmark the city typically reaches in early May and that has not occurred before March 26. It also said Las Vegas could see its hottest March stretch ever recorded, including the chance of an early Saturday 100 F reading.
At Crissy Field, the report described an atmosphere more like late summer than mid-March, with sunbathers and dogs out along the waterfront. Roger Gass, a meteorologist with the National Weather Service in the Bay Area, said it was unusual for San Francisco to run this hot this early in the year, pointing to prior occurrences—most recently in 2005, when downtown hit a record 87 F (30.5 C) on March 11, and again in March 2004 when the city saw a nearly weeklong heat wave with temperatures around 80 F (26.7 C).
For some residents, the warmth felt like a break from routine seasonal expectations. “It feels like summer already in March. That’s crazy, but I love it,” Justyce Roliz said. Others highlighted practical limitations as the heat set in, noting that many residents do not rely on air conditioning to cool off. Jessica Ling said, “We have our fans going, our windows open, but we try to be outside as much as we can.”
The heat stretched beyond coastal California and into places that usually see hotter weather earlier in the year. In Las Vegas, the report cited Brian Planz, a meteorologist at the city’s National Weather Service forecast office, who said temperatures could reach 100 F (37.7 C) Saturday and that would be the earliest Las Vegas has reached triple digits. Planz also said even if temperatures stay in the double digits, Las Vegas was poised to break its March all-time high of 93 F (33.8 C), set in 2022, and he urged visitors to plan for the conditions and hydrate.
National parks prepared for spring break crowds while issuing guidance aimed at reducing heat exposure. White Sands National Park in New Mexico could reach the mid 90s Fahrenheit (around 35 C), while Grand Canyon National Park in Arizona was under an extreme heat warning, with temperatures possible up to 104 F (40 C) in some places. Park officials advised visitors to avoid strenuous hiking during the hottest window of 10 a.m. to 4 p.m.
In the Denver area, the report also connected the current heat to longer-term water concerns. The National Weather Service said Denver had not seen three consecutive March days above 80 F (26.6 C) since 1907, but warned more warm days could return this week. The AP report said the heat wave followed an unusually warm winter that left Colorado’s mountains with less snow, reducing the snowpack that feeds water for millions of people, and that water providers in the Denver area had already enacted or were considering limits on outdoor watering.
Aurora Water, which provides water to 400,000 people in suburban Denver, told residents to avoid using sprinklers during the warm spell. Shonnie Cline, a spokesperson for Aurora Water, said temperatures could still drop below freezing later, causing any water left in sprinkler systems to freeze and break the lines. “The sooner you wake it up, it’s not necessarily better,” she said of lawns.