Today | Weather | Friday, October 9, 2026

Weather in Boulder, Colorado

02:19 PM
Now
Cloudy Weather
88° F
Feels Like 88°
Precipitation 0 %
Wind 7 mph
UV Index (0 - 11+) 3
Humidity 15 %
Today
Cloudy Weather
Day 88°
Night 61°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 4

Boulder Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (October 9, 2025)
Rainy Night

Day

82°

Night

54°

Wind

5 mph

Precipitation

49 %

Air Quality in Boulder

NOW
39 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.63 µg/m³
PM10 2.05 µg/m³
O3 0.042 ppm
NO2 0.1 ppb
SO2 0.1 ppb
CO 0.06 ppm
NH3 0.11 µg/m³
NO 0.04 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)
PM2.5 – 1.63 µg/m³
PM10 – 2.05 µg/m³
O3 – 81.88 µg/m³
NO2 – 0.15 µg/m³
SO2 – 0.32 µg/m³
CO – 65.97 µg/m³
NH3 – 0.11 µg/m³
NO – 0.04 µg/m³