Air Quality in Boulder, United States

Clear
33.4°C · 13.8% humidity
33.4°
Feels 33.4°
73
Moderate
Unusually sensitive people should consider reducing prolonged outdoor exertion.
3 stations

Nearby Monitoring Stations

AQI Forecast Calibrated
72 8am
72
72
73 11am
72
72
72 2pm
72
72
72 5pm
72
72
72 8pm
72
72
72 11pm
72
74
74 2am
72
72
72 5am
72
74
Station readings
73
CAMS model adj +47
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
27
27
25
25
25
25
27
AD 728×90

Air Quality Index Trend

5h · 1 stn

Boulder's air quality is primarily affected by vehicle emissions and industrial activity. Seasonal wildfire smoke and weather patterns can cause periodic air quality deterioration. Current PM2.5 concentration in Boulder is 1.5× the WHO 24-hour guideline of 15 µg/m³.

13.8%
Humidity
36.8 km/h
Wind E
1009.8 hPa
Pressure
14.9
UV Extreme
GoodModerateUSGUnhealthyVery UnhealthyHazardous

Which pollutant is driving the AQI?

PM2.5▲
73
22.47 µg/m³
PM10
13
13.7 µg/m³
050100150200300500

What is the weather forecast for Boulder?

Temperature & Precipitation

PM2.5 Trend

5h · 1 station
PM2.522.47 µg/m³ ×1.5 WHO
Moderate
PM1013.7 µg/m³
Good
UV INDEX14.9
Extreme
AD 300×250
Station readings (3 stations within 25 km)
22.47
Median
17.64
Average
9.6
Low
22.66
High
PM2.5 µg/m³ · Model: 5.9 · Bias: -16.6

What is the 7-day forecast for Boulder?

07-21
33.4° 17.8°
0.06 mm
07-22
35.1° 15.6°
07-23
23.9° 16.2°
1.56 mm
07-24
32.1° 17.3°
1.63 mm
07-25
35.0° 17.0°
0.75 mm
07-26
31.4° 17.9°
1.0 mm
07-27
34.0° 16.0°
Both models agree Avg diff: 4.5°C

Where are air quality stations near Boulder?

30
Athens, Boulder-CU, Colorado, USA
0.4 km PM2.5: 7.2 µg/m³
–
united-states-of-america-boulder-joslyn-court
2.5 km
–
Rocky Flats - North
13.3 km
69
Longmont Collocation 1
22.0 km PM2.5: 20.7 µg/m³
6
Longmont - Municipal, Colorado, USA
22.0 km PM2.5: 1.4 µg/m³
68
Fremont Elementary School
25.3 km PM2.5: 20.1 µg/m³
71
Westminster Town Hall
25.4 km PM2.5: 21.5 µg/m³
71
Northwest Open Space
25.8 km PM2.5: 21.7 µg/m³
66
Recreation Center, Senior Center, and Theatre
26.7 km PM2.5: 19.1 µg/m³
68
North Mor Elementary School
28.8 km PM2.5: 20.3 µg/m³

What cities are near Boulder?

66 Louisville 66 Broomfield 65 Erie 58 Longmont 65 Northglenn 63 Arvada 64 Golden 59 Thornton 63 Sherrelwood 63 Wheat Ridge
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Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-07-21T17:11 UTC.