"It doesn't happen very often in May, but I am tracking a chance of wet weather, " said Nicco.
Thursday and Friday will be the warmest days before it all changes, including a chance of rain on Cinco de Mayo.
"The sea breeze kicks in and cools us Saturday with a chance of showers Sunday into Monday morning, " said Nicco. "Monday morning we could wake up to a few slick spots."
Nicco's Accuweather forecast shows light showers in parts of the Bay Area, including San Francisco, San Jose, Livermore, Richmond, Concord, Fairfield, Fremont, Brentwood, Mountain View, Redwood City, Half Moon Bay and Calistoga.
"It's not going to be a lot of rain, less than a tenth of an inch and not all of us are going to get that rain either. It's just that time of the year," said Nicco.