Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Grannis, United States, as it serves as a vital tool for protecting your skin against harmful ultraviolet radiation. With typical UV levels soaring to a peak of 11 around midday, awareness can significantly reduce the risk of sunburn and long-term skin health issues. Grannis, located in a humid subtropical climate zone (Cfa), experiences intense sunlight, particularly during the warmer months, making it essential to stay informed about daily UV exposure risks. By keeping an eye on the UV Index, you can enjoy the outdoors safely while safeguarding your skin.
The UV Index throughout the day presents a clear trajectory of increasing intensity, peaking dramatically as the sun reaches its zenith. At 07:00, the index starts modestly at 1, signifying minimal risk. However, as the hours roll on, from 08:00 to 10:00, it climbs steadily to 6, marking the onset of moderate exposure. The real surge occurs between 11:00 and 13:00, where the index hits a staggering 11, indicating a very high risk for unprotected skin. Even as it begins to taper off in the afternoon—returning to 9 by 15:00 and further down to 4 by 17:00—the day's UV intensity serves as a reminder of the importance of sun protection. By 19:00, it drops back to a safe 1, allowing for a sigh of relief as daylight wanes. Embrace the sun wisely!
| 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 | 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 | 11 | extreme | 10 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 exhibits significant seasonal variations that affect sun exposure risks for both visitors and residents. From January to March, the UV Index begins to rise, indicating a transition from moderate levels (UV 4) in January to very high (UV 8) by March. The peak risk occurs from April to July, where the index reaches an alarming extreme level of 11, meaning people can burn in as little as 10 minutes. August and September continue to pose high risks, though slightly reduced at 10, before dropping to moderate by November (UV 5). To protect against skin damage and health risks, it is essential for individuals to practice sun safety measures, especially during the high-risk months of March through October. To minimize exposure, seek shade, wear protective clothing, and apply sunscreen regularly during these periods.
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 |
| Grannis | 4 | 6 | 8 | 10 | 11 | 11 | 11 | 10 | 10 | 8 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |