First day of triple-digit heat in 2026 arrives in Phoenix, Arizona
A heatwave has hit the Valley, causing record heatwaves and temperatures continue to rise.
A small community in Arizona broke the U.S. record for highest March temperature on March 19, reaching a scorching 110 degrees during an early heat wave in the Southwest.
Temperatures reached 110 degrees near Lake Martinez, a recreational community in southwestern Arizona about 45 minutes north of Yuma, on March 19, according to the National Weather Service.
The previous March temperature record was 108 degrees, first set in 1954 in Rio Grande, Texas. The record was also set near California’s North Shore during a heat wave on March 18, the National Weather Service said.
The news comes as Arizona, California and other southwestern states face an unprecedented multi-day early heatwave. The weather bureau said the heat was the result of a high-pressure system moving across the west, causing a “vast dome of unusually high temperatures.”
The resulting temperatures are unprecedented.
As of the morning of March 20, more than 18 million Americans remained under heat warnings across much of Southern California, southern Nevada, and Arizona. Millions more are under heat advisories.
Heatwave breaks numerous records daily and monthly
The heatwave that began earlier this week has already broken daily high temperature records in cities across the Southwest, and in some places even broken records for March.
Temperatures in Phoenix rose to 105 degrees on March 19, breaking the previous record of 97 degrees for the same day in 2017, according to the National Weather Service. Temperatures soared into the triple digits by around 1 p.m., with heat warnings in effect for metro Phoenix. Phoenix’s high temperature was about 25 degrees above normal. The first 105-degree day of the year typically occurs on May 22nd, on average, according to the National Weather Service.
The first time Phoenix’s temperature reaches 100 degrees of the year is usually around May 10, but prior to this year, the earliest day of the year to reach 100 degrees was March 26, 1988.
In the Los Angeles area, decades-old daily records have been broken since the heatwave began. On March 17, the high temperature in downtown Los Angeles reached 98 degrees, breaking the record of 94 degrees set more than 100 years ago in 1914.
California, Arizona, Nevada, New Mexico, Colorado, Oregon, Idaho, and Wyoming all set new records for March.
Contributor: Sarah Henry, Arizona Republic
