Air Quality in Longmont, United States

Drizzle
16.2°C · 37.4% humidity
16.2°
Feels 16.2°
22
Good
Air quality is satisfactory. Enjoy outdoor activities.
2 stations

Nearby Monitoring Stations

AQI Forecast Calibrated
182 6pm
23
75
75 9pm
75
88
88 12am
100
100
113 3am
113
113
113 6am
113
100
100 9am
88
88
88 12pm
88
88
88 3pm
88
88
Station readings
182
23
CAMS model adj +63
12
12
12
12
12
25
25
37
37
50
50
50
50
50
37
37
25
25
25
25
25
25
25
25
AD 728×90

PM2.5 Trend (24h)

25h · 30 stations
37.4%
Humidity
49.8 km/h
Wind NW
1006.8 hPa
Pressure
1.4
UV Low
GoodModerateUSGUnhealthyVery UnhealthyHazardous

What is the weather forecast for Longmont?

Temperature & Precipitation

PM2.55.29 µg/m³ ✓ WHO
Good
PM1013.7 µg/m³
Good
UV INDEX1.4
Low
AD 300×250
Station readings (2 stations within 25 km)
5.29
Median
5.29
Average
5.0
Low
5.58
High
PM2.5 µg/m³ · Model: 4.4 · Bias: -0.9

What is the 7-day forecast for Longmont?

04-09
17.9° 8.2°
1.63 mm
04-10
16.2° 8.9°
7.19 mm
04-11
17.5° 8.2°
5.0 mm
04-12
18.3° 7.3°
0.88 mm
04-13
15.8° 5.1°
0.31 mm
04-14
11.3° 1.1°
10.94 mm
04-15
12.5° 3.2°
0.13 mm
Both models agree Avg diff: 3.7°C

Where are air quality stations near Longmont?

21
Longmont Collocation 1
0.3 km PM2.5: 5.1 µg/m³
–
united-states-of-america-boulder-joslyn-court
20.4 km PM2.5: 0.0 µg/m³ PM10: 0.0 µg/m³
12
Platteville Middle School
24.1 km PM2.5: 3.0 µg/m³
25
Silver Creek
25.2 km PM2.5: 5.9 µg/m³
22
Anythink Brighton Library
31.3 km PM2.5: 5.2 µg/m³

What cities are near Longmont?

25 Erie 25 Louisville 23 Boulder 20 Loveland 26 Broomfield 25 Northglenn 25 Thornton 26 Sherrelwood 26 Arvada 21 Evans

Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-04-09T21:22 UTC.