(KRON) — The National Weather Service has extended the Excessive Heat Warning that takes effect Saturday morning at 11 a.m. through until 8 p.m. on Tuesday, Sept. 6. Warnings posted to the NWS website warn of “dangerously hot conditions” with temperatures of 90 to 105 degrees possible along coastal portions of the Bay Area and Central Coast. Temperatures will be higher for interior portions of the Bay Area with the NWS warning of scorching temperatures of 100 to 107 degrees possible.
Target areas for Excessive Heat Warnings
Target areas for the warnings include:
- East Bay Hills
- East Bay Interior Valleys
- Eastern Santa Clara Hills
- North Bay Interior Mountains
- North Bay Interior Valleys
- Santa Clara Valley Including San Jose
- Santa Cruz Mountains
- Sonoma Coastal Range
- Coastal North Bay Including Point Reyes National Seashore
- Marin Coastal Range
- Northern Monterey Bay
- Northern Salinas Valley, Hollister Valley and Carmel Valley
- San Francisco
- San Francisco Bay Shoreline
- San Francisco Peninsula Coast
- Southern Monterey Bay and Big Sur Coast
Warnings on the NWS website state that extreme heat “will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities.” According to the NWS, the highest temperatures will occur across interior regions and in higher terrains during the afternoon.

Temperatures overnight are expected to remain mild to warm, “providing little relief from the heat.” Closer to the coast, onshore winds and marine influences from the Pacific Ocean could limit daytime heating along the coast. Afternoon highs at the coast will remain in the 70s to 80s, minimizing heat-related risks.
There is less certainty for coastal and bay shoreline regions, with the “interaction between the high pressure and the marine layer” making it difficult to determine how high temps could get, according to the NWS.
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Tips for staying safe during the Bay Area heatwave
Tips for staying safe during the Excessive Heat Watch include:
- Monitoring the latest forecasts and warning for updates on the situation
- Being prepared to drink plenty of fluids
- Stay in air-conditioned rooms
- Stay out of the sun
- Check up on relatives and neighbors
- Don’t leave pets or children unattended in vehicles under any circumstances

Those who work or spend time outdoors are encouraged to take extra precautions and reschedule strenuous activities to early morning or evening. It’s also important to know the signs and symptoms of heat exhaustion and heat stroke. Those who work outdoors should also take frequent rest breaks in shaded or air conditioned environments.
The NWS also advises people to wear lightweight and loose fitting clothing. Anyone who is overcome by heat should be relocated to a cool and shaded location. If someone is suffering from heat strike, the NWS advises calling 9-1-1.