Today (Aug. 25) is a Spare the Air day, which means free rides on several area transit systems, including Unitrans and Yolobus.

The Sacramento Metropolitan Air Quality Management District made the declaration as a way to help deal with unhealthy air quality — the result of high temperatures. Today's forecast for ground-level ozone pollution, as measured by the Air Quality Index, is 151 — down from an earlier forecast of 161, but still "unhealthy" for everyone.

The district issues a Spare the Air advisory whenever the AQI is forecast to be 150 or higher.

Yesterday (Aug. 24), the district recorded an AQI reading of 114,  which is "unhealthy for sensitive groups." The forecast for tomorrow (Aug. 26) is 129, also "unhealthy for sensitive groups."

In declaring Spare the Air days, the district asks people to reduce their driving: less driving means less pollution from motor vehicles. Therefore, the district encourages people to postpone errands and form carpools for sports and recreation activities.

Public transit is another option — and free rides are the incentive. Besides Unitrans and Yolobus people also can ride for free on the North Natomas Transportation Management Agency shuttle, Auburn Transit, Lincoln Transit, Placer County Transit, Roseville Transit and El Dorado Transit.

More information.