Record-Breaking Heat Wave Scorches Southwest, Arizona Town Hits 110°F in March

Martinez Lake, Arizona, a desert community near the California border, reached a scorching 110°F (43.3°C) on Thursday, March 19, 2026, establishing a recent United States record for the highest March temperature ever recorded. The National Weather Service (NWS) confirmed the record-setting temperature, which was measured just outside of Martinez Lake in the Yuma Desert.

Previous Records Shattered

The previous national record for the highest March temperature was 108°F (42.2°C), set in Rio Grande City, Texas, in 1954. This record was tied on Wednesday, March 18, 2026, by North Shore, California, a small desert community. However, Martinez Lake surpassed that mark by two degrees on Thursday. Several other California locations also experienced record highs, with Cathedral City, near Palm Springs and Thermal, northeast of San Diego, both reaching 108°F (42.2°C).

Unusual Timing of the Heat Wave

The extreme heat arrived on the last day of winter, significantly ahead of schedule. The NWS noted that the average first 105°F (40.6°C) day typically occurs around May 22nd. Thermal is forecast to reach 110°F (43.3°C) on Friday, March 20, 2026, potentially tying the record.

Widespread Record Highs Across the Southwest

The heat wave has impacted numerous cities across the Southwest, with record highs reported in Phoenix, San Diego, Los Angeles, Las Vegas, and San Francisco. Phoenix reached 105°F (40.6°C) on Thursday, exceeding its previous record of 102°F (38.9°C) set the day before. Wednesday marked the earliest date Phoenix has seen temperatures exceed 100°F (37.8°C) in recorded history, and the first time above 100°F in March in nearly 40 years. Las Vegas hit 95°F (35°C), surpassing its previous record of 94°F (34.4°C).

Ongoing Heat and Fire Weather Concerns

The NWS predicts that temperatures will remain 20 to 30 degrees above normal for March throughout the rest of the week in the Southwest. A slight cooling trend is expected to begin on Sunday. The early heat, combined with gusty winds and low relative humidity, has created critical fire weather conditions from the central Rockies to the central and southern Plains. The National Weather Service is closely monitoring the situation.

Local Reactions

Despite the extreme temperatures, some residents are taking the heat in stride. Ruben Pantaleon, a car windshield cleaner in Thermal, stated he wasn’t overly concerned, noting, “It’s the desert. It gets real hot. I’m not worried about it.” He reported drinking three electrolyte drinks while working under the sun.

Safety Precautions

Due to the risk of heat illness, hiking trails around Phoenix were closed on Thursday. Authorities are urging residents to take precautions, including staying hydrated and avoiding strenuous outdoor activities during the hottest parts of the day.

The Weather Channel provides a 10-day forecast for Martinez Lake, Arizona, and surrounding areas.