Last updated: June 2, 2025
Understanding the UV Index in Greeley, United States, is crucial for everyone looking to protect their skin and overall health from harmful sun exposure. The UV Index provides vital information on the strength of ultraviolet radiation at various times of the day, helping residents and visitors make informed decisions to prevent sunburn and long-term skin damage. In Greeley's Dfa climate, where sunny days are common, UV levels can reach as high as 11 during peak hours—it’s essential to stay vigilant. By staying informed about local UV conditions, you can enjoy the outdoors while minimizing risks to your skin health.
As the sun climbs higher, the UV Index takes a dramatic leap throughout the day. Starting at a gentle 1 at 07:00, it gradually rises to 3 by 09:00. The real intensity kicks in later, peaking at an impressive 11 around 13:00, a critical time when sun protection is essential. From there, a gradual decline begins, with readings of 10 at 14:00, 9 at 15:00, and tapering off to 3 by 18:00. Finally, the day winds down, returning to 1 by 19:00. It’s a vivid reminder of how important it is to safeguard against UV exposure during the sun’s most potent hours!
| 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 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | 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, UV levels display significant variation, peaking during the summer months. The high-risk months for UV exposure are April through September, with UV Index values reaching their peak at 11 in June, indicating an extreme risk of harm from unprotected sun exposure. Visitors and residents are advised to take precautions during these months, including seeking shade, wearing protective clothing, and applying sunscreen regularly. During lower UV months, specifically January, February, November, and December, while risks are moderate, it's still wise to remain vigilant as UV rays can still cause harm. Being informed about UV Index levels can help ensure a safe and enjoyable outdoor experience year-round.
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 |
| Greeley | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 10 | 8 | 6 | 4 | 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 |