As the San Francisco Bay Area enters the seventh day of a historic heat wave, forecasters are warning people to drink plenty of water and stay inside.

Previous record highs in the city of Napa, as well in the city of Santa Rosa — both made in 1980 — were either tied or broken last week, officials said, while a third local record, set in 1930, may have been broken on Sunday.

However, the heat will not likely surpass daily records this week — and here is why. In early October 1987, a strong high-pressure ridge and Santa Lucia (northeasterly) winds triggered an intense heatwave across California.

Heat records were matched or broken Sunday across the Bay Area and beyond, surpassing temperatures from a heat wave that hit nearly 100 years ago, according to the National Weather Service. San Rafael hit the highest temps in the Bay Area on Sunday,

More scorching temperatures were expected across much of the Bay Area on Sunday with conditions predicted to cool down Monday, meteorologists said. The National Weather Service extended excessive heat warnings for several Bay Area counties,