US heatwave moves eastward, shattering temperature records across country

A blistering heatwave that swept the western half of the United States has pushed eastward into the country’s heartland, delivering unusually warm conditions to locations that were at or below freezing only a week earlier.

According to the National Weather Service Weather Prediction Center, dozens of cities from California to Colorado logged their highest March temperatures on record.

New March highs recorded yesterday included 33.3C in both Kansas City, Missouri, and North Platte, Nebraska, the agency said.

Beyond those monthly records, the heatwave set a number of other temperature benchmarks across the region.

In Phoenix, Arizona — typically one of the nation’s hottest cities — the overnight low reached a muggy 21.1C yesterday, the earliest calendar date that low has been observed there, the weather service reported.

On Friday, readings climbed as high as 44.4C in several locations along the southern California–Arizona border, marking a national U.S. record for March.

The National Weather Service issued an extreme heat warning for those same desert zones yesterday, and also raised a red flag warning — signaling elevated wildfire risk — across large portions of the central Plains in Nebraska, Kansas and Oklahoma.

Scientists point to overwhelming evidence that contemporary heatwaves are a clear indicator of global warming, a trend driven principally by the burning of fossil fuels.

With the northern hemisphere’s winter officially ending on Friday — the first day of astronomical spring — the rapid rise in temperatures has begun to disrupt wildlife across the West.

Many plants and trees are already in bloom, and vegetation is growing quickly after heavy rains in December and January fuelled early greening.