Last updated: June 2, 2025
In Evanston, United States, understanding the UV Index is crucial for protecting your skin from harmful ultraviolet rays. The UV Index provides a clear indication of sun exposure risks, helping residents prevent sunburn and maintain long-term skin health. With a Dfb climate that brings warm summers and snowy winters, Evanston experiences varying UV levels throughout the year. During peak hours, particularly between 11 AM and 2 PM, the UV Index can soar to levels above 10, posing significant risks for unprotected skin. Stay informed and safeguard your health by checking the UV Index regularly to enjoy the outdoors safely!
At dawn, the UV Index starts at a mild 1 at 07:00, gradually climbing to 2 by 08:00. As the sun rises higher, it reaches 4 at 09:00 and skyrockets to 6 by 10:00. The intensity peaks at 11:00 with a strong 9, followed by an even more intense 11 at noon. The UV rays continue to surge, hitting a maximum of 12 at 13:00 and again at 14:00. A gradual decline begins in the afternoon, dropping to 10 at 15:00 and further down to 7 by 16:00. As evening approaches, the index tapers off, settling at 5 at 17:00, 3 at 18:00, and finally retreating back to a safe 1 by 19:00. Be sure to take precautions during those peak hours when the UV Index reaches its zenith!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits significant seasonal changes that greatly influence the risk of over-exposure. High-risk months are predominantly from March to August, peaking in May and June with an extreme UV Index of 11 and 12, respectively, where the burn time is as short as 10 minutes. As spring transitions into summer, the exposure category shifts from very high to extreme, indicating that visitors and residents should exercise caution during outdoor activities, particularly between 11 AM and 3 PM when UV radiation is most intense. In contrast, months like January, February, November, and December present a lower risk, categorized as moderate, with longer burn times of 30 minutes. It's crucial for everyone to remain vigilant, wearing protective clothing, applying sunscreen, and seeking shade during peak UV hours, especially during the high-risk summer months.
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 |
| Evanston | 4 | 6 | 9 | 10 | 11 | 12 | 12 | 11 | 10 | 7 | 5 | 3 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |