(KTVU) - The Bay Area Air Quality Management District has issued a Spare the Air Alert for Sunday.
It is the third Spare the Air Alert for smog in 2017.
The district says there is no free transit tomorrow and there is not a wood burning ban in place.
Jack Broadbent, executive officer of the Air District says, "Hot temperatures and traffic exhaust are expected to cause hazy skies and unhealthy air quality in the Bay Area this weekend."
The Air District adds that outdoor exercise should only be done in the early morning hours when ozone concentrations are lower.
Residents are also encouraged to avoid driving alone.
To find out more about Spare the Air Alerts, click here.