The advisory goes into effect Thursday at 11 a.m. through Friday at 11 p.m.
Parts of the Bay Area experienced a significant warm-up on Wednesday with temperatures throughout the region predominantly in the 80s.
San Francisco reached 86 degrees, Oakland got up to 88, while San Jose saw a high of 92. As the evening wore on San Francisco maintained its heat, while Oakland was slightly cooler.
Weather officials said there is a possible threat to life or property due to the heat. Temperatures could range from the upper 80s to near 100 degrees. Skies will be sunny. Expect temperatures to be slightly cooler along the coast. The advisory was issued at 12:50 p.m.
Stream KTVU on your TV by downloading Fox Local on your Roku, Amazon Fire, AndroidTV or AppleTV device for free. More details here.
On social media, NWS Bay Area reminded followers to stay hydrated and check on neighbors if possible.
Fire danger is high, according to KTVU Meteorologist Bill Martin, but he did not indicate that there were any related advisories. Martin reminded the heat can be stressful for older people, small children and pets.
The fog is lingering on the shore, but will not make a significant appearance until Friday evening, Martin said.
The heat wave is expected to peak on Friday.