Parts of the Bay Area were baking under triple-digit heat on Thursday, with at least seven cities notching new daily records, the National Weather Service said. Santa Rosa and San Rafael both hit 100 degrees,

By noon, the weather service said temperatures in the hottest spots had risen to 94 in Livermore, and 93 in Antioch and Concord; those communities are generally the three hottest spots in the interior East Bay. In the South Bay, Morgan Hill was 94 and San Jose had reached 88.

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.