Some of the hottest weather of the season is in the immediate future for northern California this weekend. An Excessive Heat Warning continues through next Wednesday, with highs between 10 and 20 degrees above average, and lows not cooling very well, either. Tonight will be a mostly clear to clear night with mild to overnight lows ranging from the 50s in the mountains to the 60s and 70s in the foothills and the valley. Highs on Saturday will be dangerously hot in many areas, under a mostly sunny sky. Highs will range from the 90s in the mountains to the upper 90s to upper 100s for the foothills and valley.
A strong ridge of high pressure will control our weather through most of the next week. Although a trough of low pressure will move toward the West Coast it will do little to cool our weather. Tropical moisture will also move northward into northern California, making the air feel a little muggier along with the above average heat. Isolated showers and thunderstorms will be possible over the mountains, but very little rain will fall. A minor cooling trend will arrive late next week, but it will still be well above average for late August. Daytime highs will be mainly in the 90s in the mountains with 100s in the foothills and valley.