Today | Weather | Monday, September 1, 2025

Weather in Longmont, Colorado

09:04 AM

Now

57° F

Feels Like 63°

Precipitation 0 %

Wind 4 mph

UV Index (0 - 11+) 11

Humidity 71 %

Today

Day 88°

Night 52°

Precipitation 0 %

Wind 7 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.

Other:

Mostly bright and clear.

Longmont Weather Forecast Updated

36 minutes ago

Last updated on September 01, 2025 8:28 AM

Air quality in Longmont

NOW

51 AQI

Moderate air quality Dominant pollutant: PM2.5

Pollutant Concentrations:

PM2.5 7.99 µg/m³

PM10 8.40 µg/m³

O₃ 41.04 ppb

NO₂ 4.96 ppb

SO₂ 0.57 ppb

CO 170.23 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