The strong so-called Santa Ana winds from the desert caused a number of new fires to flare up on Thursday. They also favored the larger fires that California firefighters battled this week.

SVT's US correspondent Carina Bergfeldt is in Santa Rosa, near the edge of the large Kincade fire that has ravaged over 30,000 hectares.

- It is an area of ​​one fifth of London that has burned up, says Carina Bergfeldt.

Many have returned home

There, the firefighters managed to get 75 percent of the fire under control. Of the 186,000 people evacuated, only 6,000 are still in shelters. The rest have been allowed to return home.

Of the 90,000 homes that risked burning, only 120 have done so, according to a local fire chief.

But the situation remains strained.

- They managed to put out two fires but two new ones started yesterday, says Carina Bergfeldt.

Suspended electricity has attracted criticism

Extremely low humidity and long periods without rain mean that the minimum spark, for example from branches that inflate on power lines, can trigger a new fire.

- There is a humidity of 5 percent here, which can be compared to an ordinary day in Sweden, which usually has around 50 percent, says Carina Bergfeldt.

The electricity company PG&E has therefore preventively shut down the electricity in some places. But this has attracted criticism, and most of the power supplies are now up and running again.

However, once Friday night is over, the NWS weather authority estimates that the Santa Ana winds will settle for at least a week to come.