Places / Chicago, Illinois
UV index in Chicago, Illinois
Check another placeLoading today’s UV…
- Low 0 to 2
- Moderate 3 to 5
- High 6 to 7
- Very high 8 to 10
- Extreme 11+
Hour-by-hour numbers
| Time | UV index | Level |
|---|
The next few days
Each day’s UV curve and peak, drawn on the same scale so you can compare. The forecast reaches roughly four days ahead.
What to do today
About Chicago
Chicago’s lakefront, beaches and large parks offer open sky that is very different from a shaded downtown block. The forecast point is central Chicago, near the Lake Michigan shore.
When to check the UV here
A lake breeze can cool a sunny day without telling you the UV index. Read the full forecast for a beach visit or long ride, rather than relying on the current number before you leave.
Planning your time outside
Bring protection for time on the lakefront and choose a sheltered stop on a longer route. Snowy winter outings call for attention to reflected light as well as the forecast.
How to read this forecast
The chart loads hourly model data from currentuvindex.com for 41.8781, -87.6298. Times are local to this forecast point. Open Hour-by-hour numbers for the values, or compare the next few days below the main chart.
The forecast describes UV for the area, not the dose on your skin. Buildings, trees, cloud and reflective surfaces can change your exposure. It does not measure a particular beach chair, trail or street.
What time does UV drop below 3?
Read the descending side of today’s curve, then check that the later hours remain below 3. The time changes with the date and weather. See how to find the afternoon drop instead of using a fixed clock time.
What should I bring?
Plan sun protection when the forecast reaches 3 or higher. Shade, covering, a hat, sunglasses and sunscreen work together. At very high UV, arrange outdoor time around the peak rather than relying on sunscreen alone.
Nearby or similar forecasts
Related guides
Sources and local information
UV forecasts are model estimates and can differ from conditions on the ground. Live data requires JavaScript and a connection to the provider; no typical UV values are substituted if it fails. Page updated October 15, 2026. See how the data works.