Today | Weather | Wednesday, October 1, 2025

Weather in O'Fallon, Missouri

01:29 PM

Now

82° F

Feels Like 86°

Precipitation 0 %

Wind 6 mph

UV Index (0 - 11+) 11

Humidity 44 %

Today

Day 86°

Night 57°

Precipitation 0 %

Wind 5 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.

O'Fallon Weather Forecast Updated

46 minutes ago

Last updated on October 01, 2025 12:43 PM

Air quality in O'Fallon

NOW

55 AQI

Moderate air quality Dominant pollutant: PM10

Pollutant Concentrations:

PM2.5 11.89 µg/m³

PM10 58.16 µg/m³

O₃ 47.58 ppb

NO₂ 13.79 ppb

SO₂ 3.13 ppb

CO 301.76 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