UV index today  UV Index

O'Fallon UV Index Today

Day Summary

The UV index in O'Fallon, United States Flag of United States will reach a high of 8.4 today. This means a veryhigh level of sun exposure. See our tips below to stay safe!

Last checked: 2025-08-01

Hourly Forecast Chart

Today's Safety Tips

The risk is very high. It's best to stay out of the sun between 10 a.m. and 4 p.m. If you must be outside, wear protective clothing and apply sunscreen often.

O'Fallon's UV Index

O'Fallon, United States, has a UV index that varies throughout the year, generally reaching moderate to high levels during summer months and lower levels in winter, reflecting typical seasonal sun exposure patterns.

Weather Seasons

UV index

The city experiences four distinct seasons: warm, humid summers with temperatures often in the 80s and 90s (Fahrenheit), cool to cold winters with occasional snow, and mild spring and fall with changing foliage and moderate rainfall.

O'Fallon's Climate

Compared to the wider Midwest region and nearby states, O'Fallon has similar weather patterns but can be slightly warmer in summer and colder in winter than areas further south, while sharing humidity and precipitation trends common to this part of the U.S.

Hourly UV Index Trend

See the UV index hour by hour for O'Fallon. When the level is high, it's smart to find some shade.

Disclaimer

* The information on this page about the UV index in O'Fallon is for educational purposes only. It is not a substitute for professional medical advice. Always consult a doctor for any health concerns.