Last updated: July 2, 2025
Understanding the UV Index is essential for residents of Cottonwood, nestled in the Cfb climate zone, where sunny days can lead to significant UV exposure risks. Being aware of UV levels throughout the day helps in the prevention of sunburn and promotes better skin health, particularly during peak hours when the index reaches a maximum of 10 around noon. With UV levels climbing sharply from moderate in the early morning to high midday, it is crucial to take proactive steps to protect yourself and your loved ones while enjoying the beautiful Cottonwood outdoors.
At dawn, the UV Index starts off low at 1 at 07:00, making it a safe time for early risers. As the sun climbs higher, the index steadily increases, reaching 4 by 09:00. The real intensity hits around 11:00, peaking at 10 by 12:00 and 13:00, indicating a prime time for sun safety precautions like sunscreen and protective clothing. As the afternoon rolls in, the index begins to decline, dropping to 9 at 14:00 and then easing to 5 by 16:00. By 18:00, it falls to 2, and finally settles back at 1 by 19:00, allowing for safe post-sunset activities. Remember to check the UV Index throughout the day to stay protected!
| 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 | 7 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 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 |
As the year progresses, the UV Index shows significant seasonal changes that affect sun exposure risk. January and February present a moderate risk with a UV Index of 3 and 4, allowing for a burn time of 30 minutes. This risk escalates in March to a high category with a UV Index of 6 and a reduced burn time of 25 minutes. The most critical months for UV exposure are April through August, with the very high category dominating—peaking at a UV Index of 10 in June and July, where the burn time drops to just 15 minutes. Though the risk declines in September with a UV Index of 8, it still requires caution. As the year closes out, the UV Index decreases to 5 in October and 4 in November, returning to a low risk of 2 by December, allowing for a safer 45-minute exposure time. Therefore, it is crucial for visitors and residents to exercise caution and protect themselves during the high-risk months from April to September through adequate sunscreen, clothing, and avoiding peak sun hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cottonwood | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 5 | 4 | 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 |