Returning students greeted by heat wave; temperatures to top 100 in many communities

WALNUT CREEK -- As students return to classrooms across the San Francisco Bay Area on Monday, they will be greeted by sweltering temperatures as a heat wave begins blanketing the region.

It won't last long, forecasters said, temperatures should return to their normal spread by Wednesday evening.

The National Weather Service has issued an excessive heat watch for Tuesday for communities bordering the Central Valley, including eastern portions of Contra Costa, Alameda and Santa Clara counties. 

An additional heat advisory was also issued Monday afternoon. The advisory will go into effect late Tuesday morning and expire at 8 p.m. Tuesday night.

"Record or near record heat with many temperatures 100 to 105," forecasters said.

Cities included are Concord, Antioch, Livermore, Walnut Creek, Pleasanton, Pittsburg, San Ramon and Blackhawk.

NWS Meteorologist Sarah McCorkle said places like Discovery Bay, Antioch and Brentwood will likely experience the highest temperatures, but even areas like central Contra Costa County will be affected, with Concord possibly topping out at 104 degrees.

"Dangerously hot conditions," the weather service warned. "The concern is greatest for those without effective cooling and/or adequate hydration so be sure to check on your friends, neighbors, and outside workers during this heat event."

Added to the heat will be a smoke plume moving over the Bay Area from the Six River Lightning Complex Fire burning in Northern California. An air quality advisory is being issued for Monday for the region.

"Skies may be smoke and residents may smell smoke," officials said.

Air quality officials issued a Spare the Air day for Tuesday as the skies were expected to become even smokier.

"High temperatures, wildfire smoke and tailpipe exhaust are expected to impact our air quality on Tuesday," said Veronica Eady, senior deputy executive officer of policy and equity at the Air District. "We can all do our part to help reduce air pollution every day by finding alternatives to driving alone – such as working remotely or taking transit – to keep air quality healthier for all Bay Area residents."

By Wednesday, a low pressure system will begin building off the coast, bringing cooler temperatures and breezes. 

"Wednesday will still be toasty but it's starting to cool down a little bit," McCorkle said. "The weekend will be nice. It will be cool."