Last updated: June 2, 2025
Understanding the UV Index is essential for residents of Story City, United States, particularly during the summer months when UV exposure peaks. The UV Index helps you gauge the strength of ultraviolet radiation, which can lead to sunburn and long-term skin health issues if not managed properly. In Story City’s humid continental climate (Dfa), typical UV levels can soar to a maximum of 11 around midday, highlighting the importance of sun safety measures. By staying informed about daily UV levels, you can protect your skin and enjoy the outdoors while minimizing your risk of harmful effects from the sun.
As the day unfolds, the UV Index rises steadily, peaking at 11 around 1 PM—a clear signal for sun protection. Starting from a low of just 1 at 7 AM, it escalates through the morning, hitting 8 by 11 AM. At 12 PM, the intensity reaches a significant 10, before slightly diminishing to 9 at 3 PM and tapering off rapidly in the afternoon. As the sun begins to set, the UV levels drop to 4 by 5 PM, finally settling back to 1 by 7 PM. With this clear UV trajectory, staying cautious during the peak hours, especially from 11 AM to 2 PM, is essential for skin safety. Don your sunscreen and enjoy the sun responsibly!
| 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 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | 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 |
Throughout the year, the UV Index undergoes notable seasonal changes, with the highest levels typically occurring in the summer months. April signals the onset of increased UV radiation, peaking in June with an extreme UV Index of 11 and a burn time of just 10 minutes. The high-risk months for sun exposure are April to September, when values range from 8 to 11, indicating very high to extreme levels. Residents and visitors should be especially cautious during this period, taking proactive measures such as wearing sunscreen, sunglasses, and protective clothing, and seeking shade during peak sunlight hours. In contrast, the winter months of December and January present a moderate UV risk, but vigilance remains essential, as skin can still be affected by UV rays even when temperatures are cooler.
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 |
| Story City | 3 | 5 | 5 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 3 | 3 |
| 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 |