The Bay Area Air District has issued Spare the Air alerts for Saturday and Sunday because of a forecast of hot weather and light winds that is expected to lead to elevated pollution levels.

The National Weather Service has issued a Heat Advisory for 11 a.m. Saturday through 10 p.m. Sunday for most of the Bay Area besides some places along the coast and in the North Bay because of expected triple-digit inland temperatures.

The air district said the weather conditions are expected to produce elevated concentrations of ozone, otherwise known as smog.

A heat advisory map for the San Francisco Bay Area on Thursday, October 1, warns of high temperatures up to 103°F and advises staying hydrated and avoiding prolonged outdoor activity.
A NOAA graphic shows a heat advisory that has been issued across most of the interior areas of the San Francisco Bay Area and central counties of Calif., for Saturday, Oct. 3, and Sunday, Oct. 4, 2026. The Coastal Flood Advisory has been extended through Friday, Oct. 2, 2026. (NOAA via Bay City News)

On Spare the Air days, outdoor exercise is advised only in the early morning hours when smog levels are lower. The pollution is particularly harmful for young children, older adults, and people with respiratory and heart conditions, according to the air district.

Dan McMenamin is the managing editor at Bay City News, directing daily news coverage of the 12-county greater Bay Area. He has worked for BCN since 2008 and has been managing editor since 2014 after previously serving as BCN’s San Francisco bureau reporter. A UC Davis graduate, he came to BCN after working for a newspaper and nonprofit in the Davis area. He handles staffing, including coaching of our interns, day-to-day coverage decisions and management of the newswire.