A major heat event is developing across California’s Bay Area, with the National Weather Service issuing a Heat Advisory from Wednesday, September 9 at 10 AM through Thursday, September 10 at 10 PM PDT.

The advisory covers a broad area including San Francisco, San Jose, the East Bay, North Bay and parts of the Central Coast. Forecasters expect temperatures to reach 10 to 20 degrees above normal in affected areas.

The National Weather Service says the region is entering a warming and drying pattern, with moderate to locally major HeatRisk possible through Thursday.

The heat will not affect every location equally. Coastal areas may remain comparatively cooler, while inland communities are expected to experience the strongest warming. Recent forecasts have pointed to temperatures approaching the 90s and potentially higher in some inland locations.

Health officials and weather authorities are urging residents to stay hydrated, limit strenuous outdoor activity during the hottest part of the day and take extra precautions if they are sensitive to heat. The National Weather Service also warns people never to leave children or pets inside unattended vehicles because temperatures inside cars can become dangerous within minutes.

Residents across the Bay Area should monitor local forecasts as the heat develops and be prepared for rapidly changing conditions.