San Francisco, California – Temperatures will plunge into the 20s and low 30s early Friday, creating dangerous cold conditions across Bay Area valleys and along major commuter routes before sunrise.
According to the National Weather Service in San Francisco, an Extreme Cold Warning and Cold Weather Advisory are in effect from 1 a.m. to 9 a.m. Friday. The coldest inland valleys in the East Bay and North Bay could drop to 24 degrees, while much of the Santa Clara Valley, Salinas Valley and coastal areas fall to around 34 degrees.
Cities including San Jose, Livermore, Concord and Santa Rosa face the highest freeze risk. Frost may form on elevated road surfaces along Interstate 680, Interstate 580 and U.S. 101, especially in sheltered inland valleys. While widespread road closures are not expected, drivers during the early commute should watch for isolated slick spots on bridges and overpasses.
The cold poses a greater risk to vulnerable populations. Prolonged exposure can lead to hypothermia for people without adequate shelter, as well as pets and livestock. Sensitive crops and outdoor plants may suffer damage where temperatures fall below freezing for several hours.
Officials urge residents to bring pets indoors, cover exposed pipes and check on elderly neighbors. Agricultural interests in the Salinas Valley and Santa Clara Valley should protect sensitive vegetation overnight.
Temperatures will rebound after 9 a.m. Friday, but additional cold advisories are possible if clear skies persist into the weekend.
