The Air District has issued the following prescribed burn notice effective October 27-31.
- Kamryn, hills near Route 92 and I280, 55 acres, Cal Fire San Mateo-Santa Cruz Unit
- Angel Island State Park, 40 acres, California State Parks
Learn about Sonoma County - its climate, potential air pollution concerns, and current air quality. You can also view upcoming Air District events in Sonoma County and read about local efforts to improve air quality.
Sonoma County lies to the west of Lake and Napa counties, north of Marin County, and south of Mendocino County. The Air District only has jurisdiction over the southern portion of the county, which includes Santa Rosa, Petaluma, and Sonoma. Two Sonoma County representatives sit on the Air District’s Board of Directors.
The Air District has issued the following prescribed burn notice effective October 27-31.
- Kamryn, hills near Route 92 and I280, 55 acres, Cal Fire San Mateo-Santa Cruz Unit
- Angel Island State Park, 40 acres, California State Parks
The Bay Area Air District today announced $4,822,770 in funding to SAFETRANS Transportation Inc. to deploy electric school buses serving special education students across Santa Clara County. The grant will support the purchase of 14 zero-emission buses and 11 charging stations, helping to electrify transportation services for some of the region's most vulnerable students.
The Air District has issued the following prescribed burn notice effective October 17 -24, 2025.
- Hill Ranch, mountains west of Novato, 155 acres, Marin County Fire Department
- Kamryn, hills near Route 92 and I280, 55 acres, CALFIRE San Mateo-Santa Cruz Unit
- TomKat Ranch, Pescadero, 49 acres, CALFIRE San Mateo-Santa Cruz Unit
- Tolay Lake Regional Park, southeast of Petaluma, 100 acres, Sonoma County Regional Parks
The Air District has fined Marathon Martinez Refinery, which is operated by Marathon subsidiary Tesoro Refining & Marketing Company LLC, $372,500 for 13 Notices of Violation that include tank-related violations, uncertified pieces of equipment at their on-site gas dispensing facility and reporting delays.
September 22, 2025
September 15, 2025
September 11, 2025
September 10, 2025
September 2, 2025
August 26, 2025
August 26, 2025
August 25, 2025
August 23, 2025
August 22, 2025
August 21, 2025
August 19, 2025
August 18, 2025
August 14, 2025
August 12, 2025
August 11, 2025
July 30, 2025
July 28, 2025
July 23, 2025
July 17, 2025
Sonoma County’s climate is largely affected by the topography of the Petaluma, Cotati, and Sonoma valleys. Temperatures are similar in the Petaluma and Cotati valleys, while Sonoma Valley temperatures are warmer, similar to Napa Valley. Average daily temperatures range from moderate overnight to hot during the day in the summer, and cool overnight to moderate during the day in the winter. Wind patterns in the Petaluma and Cotati valleys are strongly influenced by the Petaluma Gap, with calm to mild winds typical in both Santa Rosa and Petaluma. During late afternoons in summer, fog is common in the Petaluma and Cotati valleys, and can persist until late morning the following day. Sunshine in the Sonoma Valley is plentiful. Annual rainfall ranges from 24 inches in Petaluma, 29 inches in Sonoma, and 30 inches in Santa Rosa.
Interactive Air Monitoring Stations Map
Ozone and fine particle pollution, or PM2.5, are the major regional air pollutants of concern in the San Francisco Bay Area. Ozone is primarily a problem in the summer, and fine particle pollution in the winter.
Although much of the interior of Sonoma County can get quite hot during summer, air monitoring results show that this area experiences some of the lowest ozone levels in the entire Bay Area. Gaps in the hills to the west allow fresh marine air inland on all but the hottest summer days.
PM2.5 can become elevated, particularly due to wood burning during the holiday season, but once again, air monitoring results show that this region has some of the lowest levels of PM2.5 in the entire Bay Area.
Last Updated: 4/21/2017