Heat records and already fires in California

Fanned by hot winds and very low humidity, a fire broke out before dawn on Thursday in the hills above the chic beach town of Laguna Beach, south of Los Angeles, where evacuation orders have been issued. been given in some neighborhoods. The fire, fought by more than 200 firefighters helped by water bombers, had already covered nearly 60 hectares by midday but was not progressing towards homes.

In Southern California, the meteorological services had issued an alert about these unusual heat, with temperatures that could exceed 32ºC at various points in the region. These out-of-season temperatures, which are on average 10ºC higher than seasonal norms, are expected to last until Sunday, the day of the American football championship final held in Los Angeles.

The longest winter period without rain

The heat record for a Super Bowl final, set in 1973 at nearly 29ºC – already in Los Angeles – could be broken, experts believe.  » Right now you have this system of high pressures and drier conditions on the surface (…) And also we live on a planet whose climate we have warmed up, so just from a purely statistical point of view we will witness an increase in records », notes Justin Mankin, climate specialist at the American University of Dartmouth.

This unseasonable heat also extends further north, in the San Francisco area for example where several heat records were broken for February 9, with 28.3ºC recorded in Salinas against 27.2ºC four years earlier. The hope of halting a cycle of chronic drought that had been sparked by spectacular snowfalls on the Californian peaks at the end of December did not last.

A laboratory at the University of Berkeley, specializing in the study of snow on the central Sierra Nevada, raised a sad record on Wednesday:  » longest winter period without any precipitation », with 32 consecutive dry days. The previous record was set in 1990.” What prevents fires is rain, precipitation. And this kind of heat phenomenon tends to suggest that there is a risk of having a very early start to the California wildfire season. “says Justin Mankin.  » It’s almost to the point where it feels like this season never ends “, he adds.

More than 10,000 km² of vegetation burned last year in California, the second worst year in history. The number and intensity of fires have multiplied in recent years throughout the western United States, with a very marked lengthening of the fire season, a phenomenon linked in particular to global warming.