Today | Weather | Tuesday, November 4, 2025

Weather in Boulder, Colorado

11:52 AM
Now
Cloudy Weather
73° F
Feels Like 75°
Precipitation 0 %
Wind 8 mph
UV Index (0 - 11+) 3
Humidity 16 %
Today
Cloudy Weather
Day 75°
Night 41°
Precipitation 0 %
Wind 8 mph
UV Index (0 - 11+) 3

Boulder Weather Forecast Updated

31 minutes ago
Last updated on

Weather Forecast History

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

Cloudy Night

Day

43°

Night

30°

Wind

6 mph

Precipitation

4

Air Quality in Boulder

NOW
37 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 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
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)
PM2.52.64 µg/m³
PM104.6 µg/m³
O377.66 µg/m³
NO20.39 µg/m³
SO20.17 µg/m³
CO73.58 µg/m³
NH30.15 µg/m³
NO0.13 µg/m³