Today | Weather | Tuesday, November 4, 2025

Weather in Boulder, Colorado

11:52 AM

Now

73° F

Feels Like 75°

Precipitation 0 %

Wind 8 mph

UV Index (0 - 11+) 3

Humidity 16 %

Today

Day 75°

Night 41°

Precipitation 0 %

Wind 8 mph

UV Index (0 - 11+) 3

Boulder Weather Forecast Updated

31 minutes ago

Last updated on November 04, 2025 11:20 AM

Weather Forecast History

Last Year's Weather on This Day (November 4, 2024)

Day

43°

Night

30°

Wind

6 mph

Precipitation

Air Quality in Boulder

NOW

37 AQI

Good air quality Dominant pollutant: O₃

Pollutant Concentrations:

PM_2.5 2.64 µg/m³

PM₁₀ 4.6 µg/m³

O₃ 0.040 ppm

NO₂ 0.2 ppb

SO₂ 0.1 ppb

CO 0.06 ppm

NH₃ 0.15 µg/m³

NO 0.13 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 – 2.64 µg/m³

PM₁₀ – 4.6 µg/m³

O₃ – 77.66 µg/m³

NO₂ – 0.39 µg/m³

SO₂ – 0.17 µg/m³

CO – 73.58 µg/m³

NH₃ – 0.15 µg/m³

NO – 0.13 µg/m³

View Hourly Air Quality Forecast