Smoke from fires burning across Northern California affecting air

Smoke from the Caldor Fire and other blazes burning across Northern California will continue affecting Bay Area air quality through the long weekend, officials said Friday.

Regional officials extended an air quality advisory through Labor Day, indicating that smoke may cause “intermittent and isolated pockets” of high pollution, but air quality is generally expected to remain moderate or good.

An air quality advisory — a notch lower than a Spare the Air alert — has already been in effect since Thursday.

Still, most of the smoke coming off the fires is expected to remain over far northern parts of the state and over the Sierra, according to the National Weather Service.

The air district’s forecasts show that air quality may improve along the coast and south-central parts of the Bay Area starting on Saturday, while air in the northern and eastern regions — which get less wind off the ocean — is expected to stay in the moderate range.

But people should stay alert to changing conditions and avoid outdoor exposure if the smell of smoke is present, air officials cautioned.

NWS also said that temperatures are expected to rise over the long weekend, with Sunday and Monday being the warmest.

Contra Costa and Alameda counties are expected to see the highest temperatures, with Concord expected to hit 101 degrees and Livermore 100 degrees on Monday.

North and South Bay cities should see temperatures in the low or mid-90s, while San Francisco is expected to stay in the mid-70s through the weekend. Keep track of air quality in the Bay Area and across California with The Chronicle’s air quality map.