Last updated: July 2, 2025
Understanding the UV Index is essential for residents of Heron Lake, United States, especially as the area experiences a climate characterized by cold winters and warm summers. With peak UV levels reaching a notable 10 around midday, awareness of these fluctuations is crucial to prevent sunburn and maintain skin health. Moderate to high UV exposure can pose risks even on seemingly mild days, making it vital for locals to protect themselves during sunny periods. By keeping an eye on the UV Index, residents can enjoy the outdoors safely while minimizing the risk of skin damage.
As the sun rises, the UV Index gradually climbs, beginning at a mild 1 at 7:00 AM. By 9:00 AM, it reaches 3, prompting early risers to consider sun protection. The intensity peaks at 1:00 PM with a maximum of 10, signaling the most hazardous conditions for unprotected skin. As the afternoon unfolds, the index dips from 9 at 2:00 PM to 6 by 4:00 PM, offering a brief respite. As the day winds down, the UV rays decrease, falling to 2 by 6:00 PM and returning to a safe 1 by 7:00 PM. Stay mindful of these fluctuations to enjoy the sun while safeguarding your skin!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | 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 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index demonstrates significant seasonal variation throughout the year, peaking during the summer months. Notably, June reaches an extreme UV Index of 11, with a burn time of just 10 minutes, making it the highest risk period. May and July also have very high levels, at 9 and 10 respectively, with a burn time of 15 minutes. The spring months see a steady increase, with April at 8 and a burn time of 15 minutes, while March escalates to a high level with a burn time of 25 minutes. By contrast, January, February, October, November, and December display a moderate UV Index, typically allowing for a burn time of 30 minutes. Accordingly, visitors and residents should exercise caution, especially from March through September, when UV levels are notably higher. Regular use of sunscreen, protective clothing, and limiting sun exposure during peak hours is recommended to safeguard against skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Heron Lake | 3 | 5 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 5 | 3 | 3 |
| 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 |