Phoenix is bracing for a potentially record-breaking heat wave, with temperatures forecast to exceed 100 degrees Fahrenheit as early as next week. The National Weather Service in Phoenix stated it is “becoming inevitable” that some desert communities will experience their first triple-digit temperatures of the season early next week, with current models “portending a prolonged period of record-setting and potentially unprecedented warmth.”
The forecast calls for a high of 102 degrees on Tuesday, March 17, which would surpass the previous record for the earliest 100-degree day in Phoenix, set on March 26, 1989, by 37 years. Typically, March temperatures in the city average in the mid- to upper 70s. Temperatures are expected to climb into the mid-90s by Friday, March 13, steadily increasing towards the century mark.
The unusual warmth is attributed to a combination of the ongoing La Niña weather pattern and the broader effects of climate change. La Niña, characterized by cooler-than-normal sea-surface temperatures in the tropical Pacific Ocean, typically brings warmer and drier conditions to Arizona. However, experts emphasize that climate change is exacerbating these effects.
“What we’re experiencing in the West this winter really tells us that it’s not just La Nina,” Shel Winkley, a meteorologist at the research nonprofit Climate Central, told the Arizona Republic earlier this month. “There’s likewise the climate change aspect. From the Rockies to the West Coast, pretty much every weather station that we have that’s in the NOAA network is experiencing the absolute hottest winter of record.”
This year’s meteorological winter, December to February, ended with a string of record-breaking 90-degree days in Phoenix. On February 27, the city tied its monthly and daily record with a high of 92 degrees, set in 1986. February 29 saw the record broken with another high of 92 degrees, and March 1 reached 93 degrees, also a daily record. The weekend marked the end of Phoenix’s warmest winter on record, approximately 3 degrees higher than the previous record set last year and about 20 degrees above normal.
The heat wave is expected to impact a wide swath of the Western United States, from northern Utah to southern California. The Climate Prediction Center indicates a nearly 100% probability of the heat wave occurring in some areas, a rare level of confidence in long-range forecasting. Temperatures across the region are expected to be 15-25 degrees above normal for this time of year.
Climate scientist Daniel Swain, writing on Weather West, described the forecast as “mid-summer-like” and indicated the heat is likely to persist, accelerating the melting of remaining snowpack. The National Weather Service advises limiting time outdoors between 10 a.m. And 6 p.m., drinking plenty of water, wearing lightweight clothing, and taking precautions to protect pets from the heat.