Last updated: July 2, 2025
Understanding the UV Index is essential for residents and visitors of Cortland, United States, as it plays a crucial role in sun safety and skin health. With peak UV levels often reaching 10 in the midday sun, being aware of these fluctuations can significantly help in preventing sunburn and reducing long-term skin damage. Given Cortland’s humid continental climate (Dfa), residents face unique exposure risks throughout the year, making it all the more important to stay informed about daily UV levels. By keeping an eye on the UV Index, you can enjoy the outdoors safely while protecting your skin from harmful rays.
The UV Index throughout the day showcases a dynamic pattern of sun exposure, peaking during the afternoon. At 07:00, the index starts low at 1, gradually increasing as the sun rises. By 10:00, it reaches 6, signaling a rise in sun intensity, culminating in a striking 10 from 12:00 to 13:00, indicating a high risk of harm from unprotected sun exposure. As the day progresses, the UV Index declines, dropping to 3 by 17:00, and steadily returning to 1 by 19:00. This data highlights the importance of sun protection, especially during midday when the UV Index is at its highest.
| 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 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure changes significantly, peaking during the summer months. January and February see moderate UV Index levels (3 to 5), requiring about 30 minutes of sun exposure before risking burns. However, from March to September, the UV Index escalates, hitting a peak of 10 in June and July, indicating a very high risk for sunburn with a burn time of just 15 minutes. April and May also fall in this high-risk category with UV Index values of 8 and 9. August and September slightly decrease but remain very high at 9 and 8 respectively. The UV Index drops to moderate levels again in October (6) and returns to low in December (2). Residents and visitors are advised to take precautions during the high-risk months—especially from March to September—by wearing protective clothing, using sunscreen, and limiting direct sun exposure to minimize skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cortland | 3 | 5 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 3 | 2 |
| 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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |