Overview
- The National Weather Service confirmed a 110-degree reading on March 19 in Martinez Lake, Arizona, the highest March temperature ever recorded in the United States.
- Phoenix reached 105 degrees on March 19, breaking the daily record with an extreme heat warning in effect and city hiking trails closed for public safety.
- Thermal, California hit 108 degrees on March 18, tying the prior U.S. March benchmark, as other cities posted March records including 99 in Las Vegas and 94 in downtown Los Angeles.
- Forecasters warn the West will stay 20 to 30 degrees above average through Sunday, with more triple‑digit highs possible in lower desert locations.
- NOAA’s Weather Prediction Center attributes the event to an expansive ridge of high pressure, and a World Weather Attribution analysis reported the March heat would have been virtually impossible without human-caused climate change.