Air quality action days are declared by the Washington Metropolitan Council of Governments when the air quality reaches an unhealthy level, usually from ozone levels, as determined by the EPA.
Hazy, hot and humid days during the summer months can cause the ozone level in the air to reach levels that are not safe for small children, the elderly and individuals with breathing difficulties. Ozone is produced from a variety of sources including vehicle and lawnmower exhaust and fumes from gas pumps, just to name a few. During the summer months COG reports the ozone forecast daily.