It's been a hot Labor Day for northern California, and more hot weather is coming this week. A Heat Advisory will go into effect Tuesday afternoon. A wind shift will also push more smoke into the valley and foothills later this week. Labor Day brought more sunshine and heat along with high, thin clouds to our sky, and we haven't seen the end to any of that yet. Tonight will be a fairly quiet night with some high clouds along with haze and mild temperatures. Overnight lows will range from the 30s and 40s in the mountains to the 50s and 60s in the foothills and valley. Tuesday will be a partly cloudy, hazy and hot day with highs ranging from the lower 90s in the mountains to the upper 90s and lower 100s in the foothills and valley.
A trough of low pressure will skirt northern California late Tuesday and Wednesday, delivering a wind shift which will push more smoke from the fires in the mountains down into the valley and foothills. The smoke may cool us a few degrees, but the biggest change will be the worsening air quality. Northern California will then be between a ridge of high pressure over the Rockies and another trough of low pressure over the Pacific Northwest from Thursday to Friday. We'll have a dip in our temperatures back to the seasonable range by the weekend and next Monday. Valley lows will fall from the upper 60s to the lower 60s next week while valley highs will fall from the lower and mid 100s to the lower 90s this weekend and Monday.