Wildfires have cropped up in different regions across California over the past several days as a record-breaking heat wave blankets most of the state, with more fire activity expected amid a spate of dry lightning and thunderstorms.

A dangerous heat wave has descended on much of California and the U.S. Southwest, with triple-digit temperatures expected along with a higher risk of wildfires.

The peak of the heat wave is expected Thursday and Friday, the National Weather Service said. While it’s brought hotter temperatures than in recent weeks, it is not particularly extreme in terms of all-time Southern California highs. “This is definitely more normal heat for this time of year,” Sam Zuber, an NWS meteorologist said.