Air Quality: Alerts and Forecasts – 511 Contra Costa

Air Quality: Alerts and Forecasts

Air quality forecast as of September 28, 2020

North Counties
Coast and Central Bay
Eastern District
South and Central Bay
Santa Clara Valley
5 County Map

Bay Area Air Quality Index

The Air Quality Index, or AQI, is a conversion of daily air pollution concentrations into a number between zero and 500. To make it easier to understand the health impact of any given AQI, the numbers 0-500 are divided into six color-coded ranges, with zero being the best possible air quality and 500 being the worst.

0-50 Good (G)No health impacts are expected when air quality is in this range.
51-100 Moderate (M)Unusually sensitive people should consider limiting prolonged outdoor exertion.
101-150 Unhealthy for Sensitive Groups (USG)Active children and adults, and people with respiratory disease, such as asthma, should limit outdoor exertion.
151-200 Unhealthy (U)Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion. Everyone else, especially children, should limit prolonged outdoor exertion.
201-300 Very Unhealthy (VH)Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion. Everyone else, especially children, should limit any outdoor exertion.
301-500 Hazardous (H)Emergency conditions: everyone avoid outdoor physical activity.

Spare the Air and Make a Difference

Spare the Air is a regional program sponsored by the Bay Area Air Quality Management District which lets you know whenever pollution levels threaten to reach concentrations harmful to your health.

When a Summer Spare the Air Alert is issued (between June and October), it means air quality is poor enough that people should commute by biking, ridesharing, or working from home to prevent further reductions in air quality.

Get Air Quality Alerts by Text or Email

Planning to bike to work or walk to school? Check the latest air quality alerts and forecasts before you head out or sign up for Spare the Air Alert notifications, available by both text and email.

Incentives and Programs to Help You Spare the Air

One of the most straighforward ways to improve air quality is to eliminate unnecessary single-occupant vehicle (SOV) trips. Combining two or more trips into one trip with multiple stops is one way to do this. Another way is to replace SOV trips with a more air-sparing mode of travel, like walking, biking, carpooling, taking transit, or vanpooling.

We know changing a habit can be difficult, especially when it comes to how you commute. We offer a number of programs and incentives to make starting a new transportation habit as painless as possible, including these two: