SAN FRANCISCO (CBS SF) — The Bay Area office of the National Weather Service on Friday issued a heat advisory covering a large portion of the North and East Bay on Memorial Day.

The advisory puts a majority of Marin, Sonoma and Napa counties as well as parts of Contra Costa, Alameda and Santa Clara counties under the advisory on Monday, May 31, starting at noon until 9 p.m. Monday evening.

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Above average heat with temperatures in the 90s and 100s is forecast, according to the NWS.

Additionally, Solano County will be under a more extreme excessive heat watch that will cover more counties to the east of the immediate Bay Area.

Fire officials across the Bay Area were noting that with Memorial Day marking the official start of summer, fire season is also beginning in earnest. The Contra Costa Fire Protection District tweeted about the increased fire danger with hot weather and the need for homeowners to prepare for fire season.

The Cal Fire Twitter account specifically warned campers to take care and make sure camp fires were allowed wherever they were staying.