Air Quality in Longmont, United States

Clear
31.4°C · 30.5% humidity
31.4°
Feels 31.4°
42
Good
Air quality is satisfactory. Enjoy outdoor activities.
Model forecast

Nearby Monitoring Stations

AQI Forecast
34 2pm
27
27
42 5pm
38
35
40 8pm
38
37
36 11pm
35
35
35 2am
28
27
27 5am
27
27
27 8am
27
27
27 11am
27
27
AD 728×90

Air Quality Index Trend

46h · 31 stn

Longmont's air quality is primarily affected by vehicle emissions and industrial activity. Seasonal wildfire smoke and weather patterns can cause periodic air quality deterioration.

30.5%
Humidity
23.5 km/h
Wind E
1009.9 hPa
Pressure
12.9
UV Extreme
GoodModerateUSGUnhealthyVery UnhealthyHazardous

Which pollutant is driving the AQI?

PM2.5▲
42
10.0 µg/m³
PM10
19
20.55 µg/m³
050100150200300500

What is the weather forecast for Longmont?

Temperature & Precipitation

PM2.5 Trend

46h · 31 stations
PM2.510.0 µg/m³ ✓ WHO
Good
PM1020.55 µg/m³
Good
UV INDEX12.9
Extreme
AD 300×250

What is the 7-day forecast for Longmont?

08-03
36.2° 17.4°
1.44 mm
08-04
34.0° 18.4°
0.31 mm
08-05
38.6° 13.2°
0.25 mm
08-06
35.8° 16.9°
0.25 mm
08-07
37.8° 17.1°
08-08
37.8° 21.1°
08-09
36.3° 16.6°
3.69 mm
Both models agree Avg diff: 3.3°C

Where are air quality stations near Longmont?

64
Longmont Collocation 1
0.3 km PM2.5: 18.5 µg/m³
54
Longmont - Municipal, Colorado, USA
0.3 km PM2.5: 13.5 µg/m³
76
Platteville Middle School
24.1 km PM2.5: 24.0 µg/m³
87
Silver Creek
25.2 km PM2.5: 29.1 µg/m³
71
Anythink Brighton Library
31.3 km PM2.5: 21.4 µg/m³

What cities are near Longmont?

31 Erie 31 Louisville 31 Boulder 42 Loveland 51 Broomfield 51 Northglenn 51 Thornton 51 Sherrelwood 51 Arvada 42 Evans
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Data sources: Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-08-07T23:56 UTC.