Forecast By County
Friday, December 19
Fri Sat
Placer
38
59
Sacramento
38
63
Yolo-Solano
50
59

The map below is a 1-hour snapshot. Click to view all hours recorded since midnight.
Current map

Forecast will be issued daily by noon (PST)

A "!" next to a forecast means a Spare The Air Day has been declared for that day.
 
Forecast: AQI   Pollutant
Fri. December 19, 2014:
 38 
PM2.5    
Sat. December 20, 2014:
 63 
PM2.5    
 
Extended Forecast: Condition Pollutant
Sun. December 21, 2014:
Moderate  Moderate
PM2.5    
Mon. December 22, 2014:
Moderate  Moderate
PM2.5    
Tue. December 23, 2014:
Moderate  Moderate
PM2.5    
Wed. December 24, 2014:
Moderate  Moderate
PM2.5    
 
Actual: AQI   Pollutant
Thu. December 18, 2014:
 33 
PM2.5    

Weather Conditions:
Friday, as a cold front moves through northern California, enhanced vertical mixing and moderate southeasterly winds will help to disperse pollutants in the Sacramento area, yielding Good particle levels. Saturday, light southeasterly winds will reduce pollutant dispersion in the Sacramento region, and moisture associated with lingering showers will enhance particle formation. Therefore, particle levels will be Moderate. Sunday, an upper-level ridge of high pressure will begin to build over California, reducing vertical mixing in the atmosphere. Furthermore, high relative humidity associated with fog and mist will increase particle formation in the Sacramento area, and light and variable winds will reduce pollutant dispersion. As a result, particle levels will remain Moderate.