What is the air quality in Longmont today?

The current Air Quality Index (AQI) in Longmont is 20 (Good). PM2.5 concentration is 4.8 µg/m³.

What is the temperature in Longmont right now?

The current temperature in Longmont is 11.2°C (feels like 11.2°C). Humidity is 38.4% and wind speed is 29.7 km/h.

Is it safe to go outside in Longmont?

Air quality is satisfactory. Enjoy outdoor activities. The UV Index is 0.0 (Low).

Air Quality in Longmont, United States

Clear

11.2°C · 38.4% humidity

11.2°

Feels 11.2°

Good

Air quality is satisfactory. Enjoy outdoor activities.

3 stations

Nearby Monitoring Stations

AQI Forecast

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Air Quality Index Trend

46h · 37 stn

View full history →

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.

38.4%

Humidity

29.7 km/h

Wind NNW

1012.5 hPa

Pressure

0.0

UV Low

GoodModerateUSGUnhealthyVery UnhealthyHazardous

Which pollutant is driving the AQI?

PM2.5

4.8 µg/m³

PM10▲

27.4 µg/m³

050100150200300500

What is the weather forecast for Longmont?

Temperature & Precipitation

PM2.5 Trend

46h · 37 stations

PM2.54.8 µg/m³ ✓ WHO

Good

PM1027.4 µg/m³

Good

UV INDEX0.0

Low

Station readings (3 stations within 25 km)

4.8

Median

6.1

Average

4.8

Low

7.0

High

PM2.5 µg/m³ · Model: 13.5 · Bias: +8.7

What is the 7-day forecast for Longmont?

10-21

23.4° 4.6°

10-22

14.7° 5.1°

10-23

11.8° 0.2°

3.75 mm

10-24

19.4° 11.6°

10-25

18.9° 5.9°

0.06 mm

10-26

22.2° 5.0°

10-27

15.6° 0.2°

Both models agree Avg diff: 4.2°C

Where are air quality stations near Longmont?

Longmont Collocation 1

0.3 km PM2.5: 4.8 µg/m³

Athens, Boulder-CU, Colorado, USA

22.2 km PM2.5: 4.6 µg/m³

Athens, Boulder-CU, Colorado, USA

22.2 km PM2.5: 3.6 µg/m³

Athens, Boulder-CU, Colorado, USA

22.2 km PM2.5: 3.6 µg/m³

Platteville Middle School

24.1 km PM2.5: 7.0 µg/m³

Silver Creek

25.2 km PM2.5: 6.9 µg/m³

Anythink Brighton Library

31.3 km PM2.5: 6.2 µg/m³

What cities are near Longmont?

25 Erie 27 Louisville 27 Boulder 15 Loveland 27 Broomfield 27 Northglenn 27 Thornton 28 Sherrelwood 27 Arvada 21 Evans

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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 2026-10-21T03:38 UTC.