Today | Weather | Sunday, December 14, 2025

Weather in Longmont, Colorado

06:02 AM
Now
Cloudy Night
25° F
Feels Like 21°
Precipitation 0 %
Wind 6 mph
Humidity 93 %
Today
Cloudy Weather
Day 55°
Night 30°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 2

Longmont Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (December 14, 2024)
Cloudy Night

Day

52°

Night

30°

Wind

8 mph

Precipitation

0 %

Air Quality in Longmont

NOW
25 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.59 µg/m³
PM10 1.69 µg/m³
O3 0.027 ppm
NO2 1.2 ppb
SO2 0 ppb
CO 0.08 ppm
NH3 0.22 µg/m³
NO 0 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.51.59 µg/m³
PM101.69 µg/m³
O353.74 µg/m³
NO22.2 µg/m³
SO20.08 µg/m³
CO93.91 µg/m³
NH30.22 µg/m³
NO0 µg/m³