While San Francisco still smells of smoke and is coated with ash, the situation appears to have improved Wednesday, with air quality reportedly at a less hazardous level today.
As previously reported, residents of San Francisco, the East Bay, and as far south as San Jose awoke to smoky skies and falling ash Monday, leaving city air so hazardous the residents were urged to stay indoors and avoid physical activity.
As of Tuesday afternoon, KRON 4 reports, areas in the North Bay were still experiencing air quality deemed “very unhealthy” to “hazardous” by the National Weather Service. Air in San Francisco and much of the East Bay was slightly better, clocking in as “unhealthy."
Air Quality Index from @AIRNow UPDATE as of Noon PDT. Very Unhealthy air quality right now for the majority of the #NorthBay. Stay indoors, if at all possible. For more info. visit: https://t.co/qjfO3U4sPf @AIRNow #NorthBayFires #TubbsFire #AtlasFire #NunsFire #PartrickFire pic.twitter.com/tqJBQSooUp— NWS Bay Area (@NWSBayArea) October 10, 2017
But according to a message sent to San Franciscans via Alert SF, air in the city today had been upgraded, as "SF air quality currently yellow," they said.
No, that doesn't mean SF's still smoggy skies are yellow in color (though, judging from the above timelapse video taken by Curbed SF, you wouldn't be wrong). The designation instead refers to the current Air Quality Index reported by AirNow, the EPA's air quality site.
And yellow, it seems, is good: "Hazardous" air gets a designation similar to Chanel Vamp and "very unhealthy" is a sickly maroon, "unhealthy" is red and orange means "USG," an acronym for "Unhealthy For Sensitive Groups" (the elderly, young children, and the ill). But yellow is "Moderate," meaning that "Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution." The only thing better than that is "Good," a bright green for those keeping track.
But just because we've gone yellow doesn't mean you should start gulping in great buckety lungfuls of outdoor air, as changes to wind patterns could decrease air quality once again. As noted Tuesday, any one who has trouble breathing as a result of the air should seek medical attention, and you should continue to avoid activity anywhere you can smell smoke.