Air Quality Information

Poor air quality often afflicts Sequoia and Kings Canyon National Parks, especially during summer. High ozone levels may be the most harmful pollutant here. In summer months, concentrations often exceed the federal ozone health standards.

Daily Air Quality Forecasts

Below are the most recent air quality forecasts sent via Twitter by the parks' Air Resource Advisors during the summer months. The date of the last forecast is in the lower right of each tweet.

During summer, generally May to October, these parks post daily and weekend air-quality forecasts to inform visitors and staff of expected conditions. Two forecasts are given, because lower elevations (Ash Mountain real-time data) experience different air quality than middle elevations (Giant Forest real-time data). Higher elevations (above 8500 feet) typically retain good air quality, even when lower-elevation monitors show poor air quality. Unless otherwise noted, the park air-quality forecast is for ozone only.

In addition to ozone, particulate matter is measured year-round at Ash Mountain. Called PM2.5, this is tiny particles that are 2.5 microns and smaller in size. PM2.5 originates from natural and anthropogenic sources. At high concentrations, it is a threat to public health, and impacts visibility. During episodes of high PM2.5, the park forecast will include PM2.5 information. This may occur when areas west of these parks have high PM and it is swept into the park, or during forest fires. To check visibility, please visit the Giant Forest webcam.

Ozone, people, and the parks

Ozone may have negative health effects, particularly for sensitive groups such as children, older people, and those with heart or lung disease. Increased ozone also affects park ecosystems. It causes widespread damage to sensitive vegetation, altering how plants grow, photosynthesize, and store food.

Park staff actively monitor and forecast ozone conditions at two air-quality stations in Sequoia National Park: one at Ash Mountain in the foothills and one at Lower Kaweah in the Giant Forest sequoia grove. At these sites, ozone measurements routinely exceed health standards in summer months, often showing poorer air quality than all other national park units.

For information on current fire that may be impacting air quality visit the Current Fire Information page.

For further information on regional air quality, you can check out the Environment Protection Agency's AirNow page.

You can also download the Environmental Protection Agency's AirNow smart phone app for iOS and Android.