Last updated: June 2, 2025
Understanding the UV Index is essential for residents of Lewiston, United States, where the unique Csb climate can lead to varying levels of sun exposure throughout the year. As UV levels peak during midday, often reaching as high as 10 in the summer months, being aware of these fluctuations becomes crucial for preventing sunburn and maintaining long-term skin health. By staying informed about the UV Index, you can better protect yourself and your loved ones from the harmful effects of UV radiation, ensuring a safe and enjoyable experience under the sun.
As the sun rises, the UV Index starts its ascent, with a gentle 1 at 07:00. By 08:00, it begins to climb, reaching 2, signaling a reminder to take care. The real intensity kicks in at 10:00, where the index peaks at 6, escalating to a scorching 9 by noon. The hottest moment arrives at 13:00, showcasing a dramatic 10—a level that demands serious sun protection. Although the UV level begins to drop after this peak, it remains notable; at 14:00, it settles at 9, then declines gently, hitting 3 by 17:00. As daylight fades towards the evening, it tapers off to 2 at 18:00 and finally returns to a safe 1 by 19:00. It's a vivid reminder of the sun's power throughout the day!
| 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 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index shows significant seasonal variations, indicating changes in the sun's intensity. January and December have the lowest UV levels (2), categorized as low exposure, allowing for longer burn times of up to 45 minutes. However, as we transition into February and March, the index rises to moderate (4) and high (6) categories, respectively, with reduced burn times of 30 and 25 minutes. The most critical months for sun exposure are from April to August, where the UV Index reaches its peak at 10 during June and July, classified as very high exposure with a rapid burn time of just 15 minutes. The UV levels then gradually decrease in September to high (7) and back to moderate levels in October and November. Visitors and residents are advised to take extra precautions during the high-risk months of April to August, by wearing protective clothing, applying sunscreen frequently, and minimizing sun exposure during peak hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lewiston | 2 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |
| 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 |