Records shattered as US heatwave moves eastward, causing some wild temperature swings

A person wears a hat for shade under the morning sun while walking along the Strand in Redondo Beach, California, yesterday, during a US heatwave. Photo / Patrick T. Fallon, AFP

A record-breaking heatwave afflicting the western half of the United States moved eastward today towards the centre of the country, bringing unseasonably warm temperatures to places that were at freezing or below just a week ago.

Dozens of cities from California to Colorado recorded their highest temperatures ever for the month of March, according to the National Weather Service Weather Prediction Centre.

Today, areas that saw new records for the highest temperatures in March included 33.3C recorded in Kansas City, Missouri, and North Platte, Nebraska.

In addition to monthly all-time highs, the heatwave reached several other temperature milestones.

For instance, in Chanute, Kansas, temperatures went from a record low of -10.5C on March 16 to a record high of 32.8C just four days later.

And in Phoenix, Arizona, one of the hottest cities in the US, the daily low was a balmy 21.1C today, the earliest in the year such a level had been reached, the weather agency said.

Cities recording all-time daily highs today included Denver (30C), Grand Island, Nebraska (36.6C) and Midland, Texas (36.6C).

On Saturday the heatwave had brought temperatures up to 44.4C in several areas along the southern California-Arizona border, a national US record for March.

The National Weather Service issued an extreme heat warning for the same desert areas today, as well as a red flag warning - indicating high wildfire risk - for much of the central Plains states of Nebraska, Kansas and Oklahoma.

Scientists say there is overwhelming evidence that current heatwaves are a clear marker of global warming, a process driven chiefly by the burning of fossil fuels.

With winter in the Northern Hemisphere officially ending on Saturday - the first day of astronomical spring - the soaring temperatures were wreaking havoc on wildlife in the West.

Many plants and trees are already blooming, and vegetation is growing at a fantastic clip, fuelled by heavy rains in December and January.

-Agence France-Presse