March Heat Wave Records Shattered Across North America

An extraordinary March heat wave has swept across western North America, leaving a trail of broken records in its wake. From Mexico to British Columbia, hundreds of monthly high-temperature records have fallen, culminating in the United States shattering its all-time March temperature record by a significant margin. This unprecedented event has raised concerns about the changing climate and the increasing frequency of extreme weather events.

Unprecedented Heat and Record-Breaking Temperatures

The heat wave was fueled by an exceptionally strong ridge of high pressure centered over the U.S. Southwest. This created summer-like conditions across much of the western United States and northern Mexico, with unusually warm temperatures even extending into Canada. The scope and intensity of this heat are unlike anything seen in modern records for this time of year, potentially marking the most extreme North American heat wave since the infamous 2021 heat dome.

Over the past seven days, nearly 700 monthly high-temperature records have been broken across the western and central United States. Adding to the intensity, 382 record-warm overnight low temperatures were also recorded. This consistent heat, even at night, is particularly concerning as it prevents communities from experiencing relief.

Specific Regional Impacts

• Southwest United States: The heat wave peaked on Friday with an all-time national temperature record of 44.4°C (112°F) set in multiple locations across the extreme Southwest, including near Yuma, Arizona.
• Arizona: Phoenix, Arizona, experienced its earliest 37.7°C (100°F) temperature on record on March 18th – typically, the city doesn’t reach triple-digit Fahrenheit readings until early May.
• California: San Francisco’s airport recorded a remarkable high of 31.7°C (89°F), significantly above the average daytime high of 17-18°C (64°F) for late March.
• Texas & Oklahoma: The extreme heat pushed eastward, with temperatures approaching 40°C (104°F) in Texas and Oklahoma.
• Canada: While the most extreme temperatures remained south of the border, Western Canada experienced unseasonable warmth. At least five communities in southern British Columbia recorded their warmest overnight lows ever observed in March. Ashcroft saw a low of 14.1°C on March 19th, while Osoyoos, Merritt, and Kelowna also broke overnight low records. Penticton soared to 22.0°C on March 20th, setting a new all-time March temperature record for the community.

Looking Ahead: Continued Heat

Unfortunately, relief isn’t immediate. Forecasters predict the ridge of high pressure will reintensify next week, bringing another round of temperatures 10-15°C above seasonal averages. Cities like Phoenix can expect daytime highs in the upper 30s to near 40°C for much of the week. This prolonged heat wave underscores the need for preparedness and awareness regarding the impacts of climate change.

For the latest weather updates and information, you can rely on Canada’s #1 most trusted weather brand and news source* (*2026 BrandSpark® Canadian Trust Study & 2026 Pollara Trust in Media Study). You can also find more information on extreme weather events from organizations like the National Oceanic and Atmospheric Administration (NOAA).