Today | Weather | Friday, October 30, 2026

Active Weather Warnings

Dense Fog Advisory

Weather in Boulder, Colorado

02:02 AM

Now

45° F

Feels Like 45°

Precipitation 0 %

Wind 4 mph

Humidity 67 %

Today

Day 64°

Night 43°

Precipitation 1 %

Wind 5 mph

UV Index (0 - 11+) 3

Boulder Weather Forecast Updated

35 minutes ago

Last updated on October 30, 2026 at 1:27 AM

Weather Forecast History

Last Year's Weather on This Day (October 30, 2025)

Day

55°

Night

32°

Wind

5 mph

Precipitation

2 %

Air Quality in Boulder

NOW

27 AQI

Good air quality Dominant pollutant: O₃

Pollutant Concentrations:

PM_2.5 2.51 µg/m³

PM₁₀ 3.7 µg/m³

O₃ 0.029 ppm

NO₂ 2 ppb

SO₂ 0 ppb

CO 0.10 ppm

NH₃ 0.67 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 – 2.51 µg/m³

PM₁₀ – 3.7 µg/m³

O₃ – 57.91 µg/m³

NO₂ – 3.77 µg/m³

SO₂ – 0.09 µg/m³

CO – 109.4 µg/m³

NH₃ – 0.67 µg/m³

NO – 0 µg/m³

View Hourly Air Quality Forecast

Weather Alerts and Warnings for Boulder

Moderate Expected Likely

Dense Fog Advisory

Dense Fog Advisory issued October 29 at 10:17PM MDT until October 30 at 10:00AM MDT by NWS Denver CO

Oct 30, 3:00 AM → Oct 30, 10:00 AM

WHAT: Visibility less than one quarter mile in dense fog.

WHERE: Boulder and the western suburbs of Denver, and Denver.

WHEN: From 3 AM to 10 AM MDT Friday.

IMPACTS: Low visibility could make driving conditions hazardous.

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If driving, slow down, use your headlights, and leave plenty of distance ahead of you.

Updated: Oct 30, 1:27 AM Source: NWS Alert