Air quality remains poor in the Sacramento region, with another Spare the Air day in effect Wednesday — the 15th this year. The poor conditions, unhealthy for sensitive groups, are predicted to last at least through Sunday.
An upper ridge of high pressure over Northern California will reduce circulation of the atmosphere above the region, resulting in cloudless skies and temperatures in the 90s, according to the Sacramento Metropolitan Air Quality Management District’s Spare the Air website.
The Sacramento Valley will see sunny conditions with patchy smoke, causing haze, and a high of 95 degrees Wednesday, the National Weather Service forecast said. The evening will be clear with a low of 63 degrees and some moderate winds.
The heat will persist through the end of the week, with highs of 98 in the forecast for Thursday and 97 degrees on Friday.
Clear, sunny skies will be blocked by haze through the weekend, with daytime temperatures in the low to mid-90s through Tuesday, the weather service said. Nights will remain hazy but will cool to the low 60s, according to the NWS forecast.
Morning air conditions remained good Wednesday throughout the Sacramento region, with an ozone air quality index of 14, considered good, and a PM2.5 AQI of 59, considered moderate, as of 8 a.m. PM2.5 refers to atmospheric particulate matter (PM) with a diameter of less than 2.5 micrometers, small enough to pass through the lungs.
Only Grass Valley had elevated morning ozone conditions Wednesday, with an AQI of 108, and Colfax had unhealthy levels of PM2.5.
Tuesday’s high ozone AQI for the region was 159, considered unhealthy.
Spare the Air days are designated when the AQI forecast exceeds 125. In those conditions, residents are encouraged to reduce driving.