Last updated: July 2, 2025
Understanding the UV Index in Lewiston, United States is essential for ensuring skin health and preventing sunburn as the sun's rays can be particularly intense during summer months. The UV Index provides valuable information about the strength of ultraviolet radiation at different times of the day, allowing residents to take necessary precautions. In Lewiston's Dfb climate, where seasonal variations can lead to unpredictable UV exposure, being informed about UV levels is crucial to protect your skin from harmful effects. With peak UV levels reaching as high as 11 around midday, knowing when to seek shade or apply sunscreen can make all the difference for your family's health!
As the day progresses, the UV Index rises dramatically, peaking at a striking 11 between 1:00 PM and 2:00 PM. Starting from a modest 1 at 7:00 AM, the index steadily climbs, reaching 2 by 8:00 AM and hitting 5 by 10:00 AM. The real intensity kicks in around 11:00 AM, recording an 8, before soaring to its maximum of 10 at noon. After the midday peak, the index begins to decline but still remains significant with a 10 at 3:00 PM and dips to 7 by 4:00 PM. As the sun sets, the UV radiation decreases, trailing off to a 3 at 6:00 PM and finally settling back to 1 by 7:00 PM, marking a gradual end to the day’s sun exposure. Stay protected!
| 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 | 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 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits notable seasonal variations, with the most significant increases occurring from March through September. High-risk months for UV exposure are April to August, when the index reaches extreme levels (11-12), resulting in a burn time as brief as 10 minutes. As a precaution, both visitors and residents should exercise caution during these months by seeking shade, wearing protective clothing, and applying broad-spectrum sunscreen frequently. In contrast, January, February, October, and November show moderate levels of UV exposure, with longer burn times of 30 minutes, indicating a reduced risk but still warranting protective measures when outdoors. Awareness of these changes will help individuals enjoy sun exposure safely throughout the year.
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 |
| Lewiston | 3 | 5 | 8 | 10 | 11 | 12 | 11 | 11 | 9 | 6 | 5 | 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 |