‘Very serious’ heatwave to hit California with highs of 115F over Labor Day

Forecasters are predicting potentially “record-breaking” heat in California later this week and over the Labor Day weekend, warning that extreme temperatures could pose serious health risks.

Temperatures may reach up to 115 degrees Fahrenheit (46 degrees Celsius) in the hills and valleys near Los Angeles on Sunday and Monday, warned the National Weather Service (NWS).

Heat will start building early this week, with highs across southern and central California, Nevada and Arizona reaching 100F (38C) or higher from Tuesday.

By the weekend, California’s Central Valley and most inland areas of southern California will have highs well above 100F. Stockton and Modesto are both forecast to hit 109F (43C) on Sunday, as are cities as far north as Chico and Reading.

All the way up in Yosemite Valley, home to rock faces like El Capitan and Half Dome, temperatures could reach 106F (41C) on Sunday and Monday.

Wildfire Today, a wildfire news site, reported that if these extreme temperatures come with low humidity and high winds, existing fires could be exacerbated.

The heatwave is being driven by a “heat dome”, according to the Los Angeles Times, meaning a mass of high-pressure filled with hot air.

Southern California and the southern end of the Central Valley, as well as parts of Nevada and Arizona, have been issued an “excessive heat watch” through the weekend.

Areas near Phoenix have given the more extreme “excessive heat warning”, with NWS warning of afternoon highs up to 114F (46C) this week.

The NWS office in Los Angeles has encouraged people to wear light clothing, stay hydrated and check on people who may be more vulnerable to heat-related illness, like the elderly.

Heat illnesses can range from heat cramps and sunburn to serious and potentially fatal heat stroke, where the body is unable to cool itself down.

Intense heatwaves have rocked nearly every corner of the US this summer, from short but intense heat in the Pacific Northwest to prolonged periods of stifling heat in Texas, Oklahoma and Kansas.

And as the climate crisis continues to grow, heatwaves are only likely to grow worse.

So far, the world has warmed about 1.1-1.2C above mid 19th-century temperatures. According to the United Nations leading climate science panel, as the world reaches 2C of warming, heatwaves that once occurred every 10 years will now happen about every other year.