Last updated: July 2, 2025
Understanding the UV Index is essential for residents in the Central United States, where sun exposure can vary significantly throughout the day. On sunny days, the UV Index can reach alarming levels, peaking at 12 during midday, making it crucial to be mindful of your sun safety practices. By learning to interpret UV levels, you can effectively prevent sunburn and protect your skin's health, allowing you to enjoy outdoor activities safely. With a semi-arid BSk climate characterized by warm summers and moderate sunshine, awareness of UV radiation risks is vital for safeguarding your well-being year-round. Remember, when the UV Index climbs, so should your sun protection efforts!
The UV Index peaks dramatically as the day unfolds, starting at a modest 1 in the early morning hours of 07:00 and 08:00. By 09:00, it climbs to 3, signaling a budding intensity. As the clock strikes 10:00, the index reaches 5, offering a hint of the sun's power. The intensity escalates rapidly, hitting a striking 8 by 11:00, and then surging to a sizzling 11 at 12:00—a time for caution. The zenith occurs at 13:00 and 14:00, with the UV Index soaring to 12, prompting you to seek shade and protect your skin. As afternoon wanes, the levels begin to gradually decline: from 11 at 15:00 to 8 at 16:00, then settling at 6 by 17:00. The evening brings relief as the index drops back to 3 by 18:00, and finally back to 1 as dusk approaches at 19:00. Stay alert and safeguard yourself during the sun's fiercest hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 11 | extreme | 10 min |
| 16:00 | 8 | very high | 15 min |
| 17:00 | 6 | high | 25 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences significant seasonal changes, with the highest levels occurring in the summer months. From May to August, the UV Index ranges from 11 to 12, classifying these months as having an extreme exposure category, meaning the risk of harm from unprotected sun exposure is very high. Specifically, March to September are identified as high-risk months, where the burn time drastically decreases to as little as 10 minutes in peak summer. Visitors and residents are strongly advised to take precautions during these months, such as wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade to minimize UV exposure and protect skin health. As the year progresses towards fall and winter, the UV Index decreases, with January, November, and December classified as moderate, allowing for safer sun exposure, though caution is still recommended.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Central | 4 | 7 | 8 | 10 | 11 | 12 | 12 | 11 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |