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Banner with Colorado and CDPHE logos on left with text on right reading Colorado Air Quality with Department of Public Health and Environment on the next line.

Detailed Air Quality Summary for 12/15/25 (Yesterday)

Learn more about monitoring sites: site descriptions and
real-time monitoring map

All data are collected real-time and have not been corrected nor validated.

Daily Highs:

Area Site Air Quality Max AQI Pollutant Conc. Period Time *
(MST)
Denver METRO
[expand +]		 ADB Moderate 61 Particulate < 10 micrometers 75 µg/m3 24-hour 12 AM
Ft. Collins - Greeley
[expand +]		 PMS Moderate 67 Particulate < 2.5 micrometers 17 µg/m3 24-hour 10 AM
Colorado Springs
[expand +]		 MAN Good 40 Ozone 43 PPB 8-hour 8 AM
Grand Junction
[expand +]		 GJPB Good 47 Particulate < 2.5 micrometers 8 µg/m3 24-hour 8 PM
Pueblo
[expand +]		 PFS Good 44 Particulate < 2.5 micrometers 8 µg/m3 24-hour 1 AM
Colorado River Valley
[expand +]		 RIFL Good 31 Particulate < 2.5 micrometers 5 µg/m3 24-hour 3 PM
Four Corners
[expand +]		 PAG Good 41 Particulate < 10 micrometers 44 µg/m3 24-hour 12 AM
Steamboat Springs
[expand +]		 SSMB Good 39 Particulate < 10 micrometers 42 µg/m3 24-hour 12 AM
Aspen
[expand +]		 ASPN2 Moderate 75 Particulate < 10 micrometers 103 µg/m3 24-hour 12 AM
Other
[expand +]		 DELT Moderate 59 Particulate < 2.5 micrometers 13 µg/m3 24-hour 8 PM

Area Site Visibility Max VSI 4-hour Average
(1/km)
 Beta Extinction
(1/km)
 Time *
(MST)
Denver DES Moderate 70 0.061 0.064 4 PM

* All data are reported in Mountain Standard Time (MST). During daylight savings time add one hour to the reported hour.