California's most significant heat wave of summer peaked in most of the Bay Area on Thursday and a cooldown will begin Friday, but not all at once.

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.