Last updated: July 2, 2025
In Thief River Falls—a charming city known for its distinctive Dfb climate—being aware of the UV Index is crucial for protecting your skin and overall health. Understanding UV levels matters not just for avoiding painful sunburns, but also for mitigating long-term skin damage that can lead to more serious health issues. During the summer months, the UV Index can peak at an impressive 9 around midday, making it essential for residents and visitors alike to stay informed about daily UV exposure risks. By staying proactive and informed, you can enjoy the beautiful sunny days in Thief River Falls while safeguarding your skin’s health.
From dawn to dusk, the UV Index steadily climbed, beginning at a gentle 1 at 07:00 and peaking at a robust 9 by 13:00. As the sun reached its zenith, the intensity of ultraviolet radiation surged, marking 12:00 with an impressive 8 and 13:00 with a near-maximal 9. The intensity gradually waned in the afternoon, dropping to 7 at 15:00, before tapering off to 4 by 17:00 and cooling to a soft 1 by 19:00. Stay protected during those peak hours to enjoy the sunshine safely!
| 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 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 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 |
As the seasons change, so does the UV Index, which is crucial for understanding sun exposure risks. From January to February, the UV Index starts low at 2, indicating a minimal risk of harm, but it gradually rises to 3 in February, marking a moderate exposure category with a burn time of 30 minutes. The risk intensifies significantly from March to August, peaking at 9 during June and July, where the burn time reduces to just 15 minutes under very high risk. May and August also remain dangerous with an 8 rating. As fall approaches, the UV levels drop, presenting a high risk of 7 in September, then decrease again to moderate and low levels by October through December. Visitors and residents are advised to protect themselves during high-risk months, particularly from late spring through summer, by wearing sunscreen, protective clothing, and seeking shade whenever possible, as sun exposure can lead to serious skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thief River Falls | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 7 | 4 | 2 | 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 |