Monsoonal moisture arriving from the south will bring shower chances throughout the day and an increase in clouds.
LIVE: Track rain in San Francisco Bay Area with Live Doppler 7
The biggest impact may be wet roads.
While it will feel uncomfortably humid, high temperatures will be 20 degrees cooler compared to Tuesday.
Any shower would be light and just a few hundredths of an inch of rain. Shower chances will diminish near midnight with drier weather returning Thursday.
This comes just a day after some cities inland saw triple-digit heat, and San Francisco saw nearly 90-degree weather.