Last updated: July 2, 2025
In Grannis, United States, being aware of the UV Index is crucial for protecting your skin and overall health. Understanding UV levels helps you prevent sunburn and reduce the risk of long-term skin damage, especially during those peak hours when values soar above 8. With Grannis nestled in a humid subtropical climate (Cfa), residents and visitors can expect intense sun exposure, particularly in the summer months. As the UV Index can reach a maximum of 11 during midday, staying informed is essential for safeguarding your skin during outdoor activities. Be proactive—check the UV Index before stepping out and ensure you're taking the necessary precautions!
The UV Index for the day showcases a striking pattern, starting moderate at 7:00 AM with a value of 1. As the sun climbs higher, the index steadily rises, hitting 3 by 9:00 AM, and then surging to a peak of 11 between 1:00 PM and 2:00 PM. This indicates a high risk of harm from unprotected sun exposure during midday. Following the peak, the UV Index gradually declines to 4 by 5:00 PM and further decreases to 1 by 7:00 PM, emphasizing the critical importance of sun protection during the intense midday hours. It’s advisable to seek shade and wear sunscreen if you're outside during the peak period!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 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 | 7 | 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 |