Where is the air worst in Colorado right now?

Longmont has the highest current reading at AQI 59 (Moderate).

How often are readings updated?

Monitors report every hour. We refresh this page with the latest hour from EPA AirNow.

Colorado Air Quality

Current AQI at 30 monitors, highest 59 (Moderate) · Measured 10/30/2026, 2:00 AM PT

Monitors: 30
Highest AQI: 59; Moderate
Typical (median): 28; Good
Above 100: 0

Monitoring sites in Colorado

Worst first. Times are local.

59LongmontModerate · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
55Ft. Collins - CSU FacilitiesModerate · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
53Denver - CAMP - 2105 BroadwayModerate · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
52GlobevilleModerate · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
51I25 DenverModerate · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
46Denver - NJH - 14th Ave. & Albion St.Good · Fine particles (PM2.5) · Fri 10/30/2026, 2:00 AM MDT
46La Casa NCORE - 4545 Navajo St.Good · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
41Greeley HospitalGood · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
40Mesa Verde NPGood · Ozone · Fri 10/30/2026, 2:00 AM MDT
39Rocky Mountain NPGood · Ozone · Fri 10/30/2026, 2:00 AM MDT
36Colorado CollegeGood · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
31Rocky Flats - N - 16600 W. Colo. Hwy. 128Good · Ozone · Fri 10/30/2026, 2:00 AM MDT
30GothicGood · Ozone · Fri 10/30/2026, 2:00 AM MDT
28Cortez OzoneGood · Ozone · Fri 10/30/2026, 2:00 AM MDT
28Golden - NREL - 2054 Quaker St.Good · Ozone · Fri 10/30/2026, 2:00 AM MDT
26Boulder - CU - 2102 Athens St.Good · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
25Chatfield Park - 11500 N. Roxborough Park Rd.Good · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
24Manitou SpringsGood · Ozone · Fri 10/30/2026, 2:00 AM MDT
22DeltaGood · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
21Ute 3Good · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
20Highland Reservoir - 8100 S. University Blvd.Good · Ozone · Fri 10/30/2026, 2:00 AM MDT
19Palisade OzoneGood · Ozone · Fri 10/30/2026, 2:00 AM MDT
19Ute 1Good · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
19Yellow Brick BuildingGood · Fine particles (PM2.5) · Fri 10/30/2026, 3:00 AM MDT
18Fort Collins - West - Laporte Ave. & Overland Tr.Good · Ozone · Fri 10/30/2026, 2:00 AM MDT
16Greeley - Weld Co. Tower - 3101 35th Ave.Good · Ozone · Fri 10/30/2026, 2:00 AM MDT
157004Good · Ozone · Fri 10/30/2026, 2:00 AM MDT
13Colorado Springs - USAF AcademyGood · Ozone · Fri 10/30/2026, 2:00 AM MDT
9Welby - 78th Ave. & Steele St.Good · Ozone · Fri 10/30/2026, 2:00 AM MDT
7Rifle OzoneGood · Ozone · Fri 10/30/2026, 2:00 AM MDT

By county

Highest current AQI among the county's monitors

Frequently asked questions

Where is the air worst in Colorado right now?: Longmont has the highest current reading at AQI 59 (Moderate).
How often are readings updated?: Monitors report every hour. We refresh this page with the latest hour from EPA AirNow.

Source: EPA AirNow · Last updated 10/30/2026 · Data are preliminary and subject to change

What the AQI means

0-50Good. Air quality is satisfactory and poses little or no risk.
51-100Moderate. Acceptable. A few unusually sensitive people may have symptoms.
101-150Unhealthy for Sensitive Groups. People with heart or lung disease, older adults, children and teens should limit long or heavy outdoor exertion.
151-200Unhealthy. Everyone may begin to feel effects. Sensitive groups should avoid long or heavy outdoor exertion.
201-300Very Unhealthy. Health alert: the risk of health effects is increased for everyone.
301-500Hazardous. Health warning of emergency conditions. Everyone is more likely to be affected.

Data sources

AirNowU.S. Environmental Protection Agency · Official site

Data as of 10/30/2026

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About this data

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