UV Index in Chicago, United States

Last updated: May 3, 2025

In Chicago, where the summers can be delightfully sunny but fleeting, awareness of the UV Index is crucial for protecting your skin. Understanding UV levels is essential not only for preventing painful sunburns but also for safeguarding long-term skin health. With the city's climate classified as Dfa, the UV exposure can peak during the midday hours, reaching levels as high as 9 around noon. This means that even on moderate days, the potential for skin damage is significant. Stay informed and take proactive measures to enjoy the sun safely!

Hourly UV Index in Chicago

The UV Index reveals a dynamic pattern throughout the day, starting at a mild 1 at 07:00 and steadily rising as the sun reaches its peak. By 10:00, it escalates to a moderate 6, reaching 8 at 11:00 and peaking at an intense 9 from 12:00 to 13:00. This period signifies the greatest caution for sun exposure, making it essential to seek shade and wear protective clothing. As the afternoon unfolds, the index begins to dip, dropping to 8 at 14:00, then declining further to 7 by 15:00, and tapering down to 1 by 19:00. Overall, it’s a day that encourages sun safety awareness, particularly during the midday hours when UV radiation is at its strongest.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
TimeUVICategoryTime to Burn
07:001low45 min
08:002low45 min
09:004moderate30 min
10:006high25 min
11:008very high15 min
12:009very high15 min
13:009very high15 min
14:008very high15 min
15:007high25 min
16:005moderate30 min
17:003moderate30 min
18:001low45 min
19:001low45 min

Monthly UV Index Trends in Chicago

Throughout the year, UV index levels fluctuate significantly, with notable increases during the warmer months. January and February experience a moderate UV index of 3 and 4, allowing for a 30-minute burn time under the sun. As the seasons transition into March and onward, the risk escalates, peaking in June and July with a maximum UV index of 10—classifying these months as high-risk. During these summer months, individuals are advised to limit sun exposure to just 15 minutes to prevent skin damage. The trend continues with August and September maintaining high levels (UV index of 9 and 8 respectively) before tapering off in October (UV index 6) and returning to moderate levels in November and December (UV index of 4 and 2). Residents and visitors should prioritize sun protection, especially during the peak months of April through September.

Monthly Maximum UV Index for Chicago, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Chicago. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec34689101098642
Data source: Statistical UV Index data for Chicago, based on information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

Compare Chicago UV Index with Other United States Cities

The table above highlights how UV exposure in Chicago compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.
Chicago's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
 JanFebMarAprMayJunJulAugSepOctNovDec
Chicago34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975