Sacramento temps to drop roughly 20 degrees — but air quality is only getting worse

Yes, Sacramento is going to get relief from the triple-digit heat — but the air quality is only going to get worse as forests burn less than 70 miles from the capital, forecasters predict.

Winds will move cooler temperatures into the area while dispersing pollutants that worsened the region’s air quality during the heat wave, according to AirNow. At the same time, though, it will move particulate matter from nearby fires into the foothills and eventually, downtown Sacramento.

Sacramento’s excessive heat warning ends at 8 p.m. Friday. Cooler air will push high temperatures back into the low 90s to high 80s, according to the National Weather Service. That’s a roughly 20-degree drop from the 110 degree temperatures downtown Sacramento hit Thursday.

The closer you are to the burn site in the Tahoe National Forest, weather service meteorologist Sierra Littlefield said Thursday, the worse the smoke is going to be.

Not only is the Sacramento region fighting smoke from the Mosquito Fire, it’s also battling wildfire smoke from the Oregon.

“These conditions will cause particle levels to be unhealthy in Placer and Sacramento Counties...with unhealthy for sensitive groups particle levels expected in El Dorado and mid-to-high moderate particle levels expected in Yolo and Solano Counties,” AirNow wrote on its website.

Spare the Air reports the Sacramento region will reach unhealthy — in some areas hazardous — levels Friday up until at least Monday.

The Mosquito Fire leaped the Middle Fork of the American River Thursday, blazing south from Placer County into El Dorado County.

Sacramento Regional Spare the Air issued an air alert Friday morning.

The AQI in Auburn reached hazardous levels at 420 due to particulate matter (PM2.5) Friday morning.

Smoke being pushed into the foothills was forecast to reverse and travel toward the Sacramento area overnight Thursday to Friday, Littlefield said. By early Friday morning, smoke from the fire might be seen and smelled in Citrus Heights, Fair Oaks, Roseville, Rocklin and Folsom.

Downtown Sacramento could also experience some smokiness too, Littlefield said, especially by Friday evening. AirNow’s Friday ozone forecast is 122 and and AQI for particulate matter is 151 (unhealthy).

“Air quality can change quickly at different times during the day due to wind shifts and vertical mixing,” Spare the Air wrote on its website. “If you see or smell smoke in your area you should stay indoors and avoid outdoor activities.”

As of Friday morning, particulate matter levels were “Good” in downtown Sacramento and Arden Arcade, according to the Spare the Air alert. Roseville had reached moderate PM2.5 levels and Folsom had unhealthy levels.

This story was originally published September 9, 2022 at 5:00 AM.