Today | Weather | Sunday, September 7, 2025

Weather in Boulder, Colorado

12:14 AM

Now

64° F

Feels Like 63°

Precipitation 47 %

Wind 7 mph

Humidity 57 %

Today

Day 82°

Night 61°

Precipitation 55 %

Wind 10

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

Last updated on September 06, 2025 11:12 PM

Air quality in Boulder

NOW

82 AQI

Moderate air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 25.25 µg/m³

PM10 37.24 µg/m³

O₃ 36.49 ppb

NO₂ 14.28 ppb

SO₂ 0.53 ppb

CO 306.93 ppb

PM_2.5 – Fine particles <2.5μm

PM₁₀ – Inhalable particles <10μm

O₃ – Ozone

NO₂ – Nitrogen dioxide

SO₂ – Sulfur dioxide

CO – Carbon monoxide

Health Recommendations:

Air quality is currently in the acceptable range. However, sensitive individuals should be aware of potential risks from certain pollutants.

View Hourly Air Quality Forecast