Summer 2008 California Wildfires - Air Quality

Air Quality

Air quality in northern and central California, especially in the Central Valley from Bakersfield to Redding, deteriorated as a result of smoke from the wildfires. From June 21 to 27, much of Northern California was covered in a thick blanket of smoke, which reduced visibility and turned the sky yellow and the moon red. Some areas endured record levels of air pollution, along with hazardous concentrations of particulate matter. These smoky and hazy conditions prompted health officials to issue air quality advisories and warnings, as particulate matter reached unhealthy levels in the North Bay on June 25. In the San Francisco Bay Area, the Bay Area Air Quality Management District urged the elderly and people with respiratory problems to stay indoors. In spite of the warnings, health officials noted a jump in the number of people with eye and throat irritation. The bad air quality also forced the cancellation of the 100 miles (161 km)-Western States Endurance Run, the first in the race's 31-year history. Air quality began to improve on June 28, followed by decreased smoke and improved visibility a day later. By June 30, residents in the Sacramento Valley saw blue skies and good air quality, as a result of onshore winds and the Delta breezes. However, air quality in Oregon degraded as plumes of smoke drifted northward instead of concentrating in the Central Valley.

Hazy conditions returned on July 7, along with high temperatures over 100 °F (38 °C) in the Central Valley. The heat and smoke combined forced public health officials and Gov. Arnold Schwarzenegger to issue Spare the Air advisories and an emergency plan for heat waves, respectively. Air quality districts issued another Spare the Air day for July 8, July 9, and July 10, as calm wind conditions in Northern California failed to blow away the smoke from the wildfires.