Today | Weather | Thursday, February 26, 2026

Active Weather Warnings

Fire Weather Watch

Weather in Longmont, Colorado

03:46 AM

Now

46° F

Feels Like 39°

Precipitation 48 %

Wind 9 mph

Humidity 41 %

Today

Day 64°

Night 36°

Precipitation 7 %

Wind 15 mph

UV Index (0 - 11+) 4

Longmont Weather Forecast Updated

6 minutes ago

Last updated on February 26, 2026 at 3:40 AM

Weather Forecast History

Last Year's Weather on This Day (February 26, 2025)

Day

50°

Night

23°

Wind

6 mph

UV Index

Precipitation

40 %

Air Quality in Longmont

NOW

28 AQI

Good air quality Dominant pollutant: O₃

Pollutant Concentrations:

PM_2.5 0.51 µg/m³

PM₁₀ 0.86 µg/m³

O₃ 0.030 ppm

NO₂ 0.3 ppb

SO₂ 0.1 ppb

CO 0.08 ppm

NH₃ 0.15 µg/m³

NO 0 µg/m³

PM_2.5 – 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)

PM_2.5 – 0.51 µg/m³

PM₁₀ – 0.86 µg/m³

O₃ – 58.4 µg/m³

NO₂ – 0.51 µg/m³

SO₂ – 0.19 µg/m³

CO – 90.18 µg/m³

NH₃ – 0.15 µg/m³

NO – 0 µg/m³

View Hourly Air Quality Forecast

Weather Alerts and Warnings for Longmont

Minor Past Observed

Fire Weather Watch

The Fire Weather Watch has been cancelled.

Feb 26, 11:00 AM → Feb 26, 5:00 PM

The Fire Weather Watch has been cancelled and is no longer in effect.

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A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings.

Updated: Feb 26, 3:40 AM Source: NWS Alert