Today | Weather | Wednesday, October 15, 2025

Weather in Boulder, Colorado

10:07 AM
Now
Cloudy Weather
61° F
Feels Like 64°
Precipitation 20 %
Wind 5 mph
UV Index (0 - 11+) 11
Humidity 59 %
Today
Sunny with a Chance of Thunderstorms
Day 73°
Night 48°
Precipitation 55 %
Wind 10 mph
UV Index (0 - 11+) 11

Warning: Extreme UV Index Today: 11+

Overexposure to the sun's harmful UV rays can cause sunburn and increase the risk of developing skin cancer, including melanoma. Protect yourself by wearing clothing that covers your skin, sunglasses, and a hat. Apply a broad-spectrum sunscreen with an SPF of 30 or higher every two hours, even on cloudy days. Minimize direct sun exposure during peak hours (10 AM to 4 PM) to reduce the risk.

Boulder Weather Forecast Updated

Air Quality in Boulder

NOW
17 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 0.5 µg/m³
PM10 0.5 µg/m³
O3 0.018 ppm
NO2 0.8 ppb
SO2 0 ppb
CO 0.08 ppm
NH3 0.12 µg/m³
NO 0.86 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)
PM2.50.5 µg/m³
PM100.5 µg/m³
O336.28 µg/m³
NO21.42 µg/m³
SO20.01 µg/m³
CO92.68 µg/m³
NH30.12 µg/m³
NO0.86 µg/m³