(KTVU) A Spare the Air alert has been issued in the Bay Area for Thursday because hot temperatures, light wind and vehicle exhaust are expected to combine to create unhealthy smog levels, regional air quality officials said.
The alert, the 10th issued so far for smog in 2017, is because of particularly unhealthy ozone levels expected in the South Bay and East Bay, according to the Bay Area Air Quality Management District.
Last year, 27 Spare the Air alerts were issued – a record high for the air quality district, according to its own records dating back to 1991. In 2015, nine alerts were issued.
"Extreme heat starting late this week is expected to cause unhealthy air quality in the Bay Area likely through the Labor Day weekend," air district executive officer Jack Broadbent said in a statement.
In the Bay Area, the summer Spare the Air season generally runs from April through October when clear skies, hot temperatures, lighter than usual winds, and strong temperature inversions combine to create smoggy conditions. Spare the Air Alerts are declared for days forecast to have ozone concentrations that exceed federal health-based standards. On Friday, an excessive heat warning is issued for much of the Bay Area, including places like Livermore, where temperatures are expected to reach 115 degrees.
To find out when a Spare the Air alert is in effect, people can register at www.sparetheair.org, call (800) HELP-AIR, download the Spare the Air smartphone app or connect with Spare the Air on Facebook or Twitter.