UV Index
UV Index
Today's UV index in Chicago, United States 
will be up to 7.5, indicating a high level of sun exposure for the average person. Check our tips for today to make sure you're safe in the sun.
Last checked: 2025-05-21
With Chicago's UV index reaching 7.5, protect your skin from harm by staying in shade, wearing protective clothing, and applying SPF 30+ sunscreen every 2 hours, especially between 10 a.m. and 4 p.m. when UV rays are strongest.
Chicago's UV index varies widely throughout the year, often highest in summer months reaching 7 to 9, indicating strong sun exposure, and lowest in winter, sometimes near 0 or 1, meaning very weak UV rays. The city experiences four distinct seasons: cold, snowy winters; warm, humid summers; mild springs; and colorful, cool autumns. Snowfall is common in winter, and thunderstorms can happen in summer. Compared to other cities in the Midwest, Chicago tends to have colder winters because of its location near Lake Michigan, which also affects local weather. Neighboring states like Indiana and Wisconsin share similar weather patterns, but Chicago's lakefront can make its climate feel a bit different.
See the UV index hour by hour for Chicago, along with the temperature and how cloudy it is. If the UV level is higher than moderate, it's best to avoid direct sunlight.