UV Index Today in Chicago, Illinois
Hourly UV Index Chart
Safe Exposure Time
Estimated based on the Fitzpatrick scale for skin color and a UV Index of
*Estimate assumes proper application of broad spectrum sunscreen with reapplication every 2 hours.
Important Safety Information
General Guidelines
These exposure times are estimates based on scientific research and should be used as general guidelines only. Individual responses to UV exposure may vary.
Affecting Factors
UV exposure is affected by: time of day, season, altitude, cloud cover, reflection from surfaces, and individual skin sensitivity.
Protection Tips
For proper sun protection: seek shade during peak UV hours (10 AM - 4 PM), wear protective clothing, use broad-spectrum sunscreen, and monitor the UV index regularly.
Medical Advice
Consult with a healthcare provider for personalized sun protection advice, especially if you have a history of skin conditions or are taking medications that may increase sun sensitivity.
SUNSET & SUNRISE
Chicago's UV Climate
Chicago, located on the shores of Lake Michigan, experiences a humid continental climate with moderate to high UV exposure during the summer months. The city's northern latitude and frequent cloud cover reduce UV intensity compared to southern cities, but clear summer days can still bring high UV levels. Residents and visitors should use sun protection during outdoor activities, especially near water where reflection increases exposure.
Average Annual UV Index
6.2
Peak UV Season
May - September
Sunny Days per Year
189
Practical Tips for Outdoor Activities
Make the most of outdoor activities while staying safe in Cook County:
- Check UV index and weather radar before planning outdoor activities
- Schedule outdoor activities during low UV hours
- Use appropriate sun protection based on UV levels
- Stay hydrated during outdoor activities
- Take regular breaks in shaded areas
- Monitor weather conditions for changes
- Be prepared for sudden weather changes
- Know the signs of heat-related illness
- Wear a hat and protective clothing
- Check visibility conditions before outdoor plans
- Stay alert to weather alerts and warnings
UV and Weather in Cook County
Learn about Cook County's unique climate patterns, UV radiation levels, and how they affect your daily life. Enter your zip code for location-specific weather radar data and UV forecasts to help you make informed decisions about outdoor activities and sun protection.
Climate and UV Patterns
Chicago's climate features cold winters and warm, humid summers. UV index values are highest from late spring through early fall, with peak values reaching 8-9 on clear days. The lake effect can moderate temperatures but does not significantly reduce UV exposure. Cloud cover is common, but when skies are clear, UV radiation can be intense.
UV Index and Health Impact
Understanding UV radiation levels is crucial for protecting your health. The UV index in Cook County varies throughout the year:
- Summer (April-September): High to Very High UV (7-10+)
- Spring/Fall: Moderate to High UV (5-7)
- Winter: Moderate UV (4-6)
- Peak UV hours: 10 AM - 4 PM
- Cloudy conditions: UV reduced by 20-40%
- Clear skies: Maximum UV exposure
- Visibility conditions affect UV intensity
Local Weather Patterns
Chicago's weather is highly variable, with frequent changes in cloud cover and temperature. Summer brings the highest UV exposure, especially during midday hours. The presence of Lake Michigan can increase UV reflection, making sun protection important for beachgoers and boaters. Winter UV levels are low but not negligible, especially on sunny, snowy days.