Last updated: May 3, 2025
In Merrillan, Wisconsin, being aware of the UV Index is essential for maintaining skin health and preventing sunburns. Understanding the daily UV levels empowers residents and visitors to protect themselves from the harmful effects of excessive sun exposure. Due to its Dfb climate—which features warm summers and cold winters—Merrillan experiences varying UV exposure throughout the year. On sunny days, UV levels can peak around 8 during midday hours, making it crucial to plan outdoor activities thoughtfully. Prioritize your skin's wellbeing by staying informed about UV Index readings and taking necessary precautions!
The UV Index throughout the day presents a clear and vigorous pattern of intensity. As the sun rises at 07:00, the index starts at a gentle 1, indicating minimal risk. By 08:00, it climbs to 2, still in the low range, but things escalate quickly; by 09:00, it reaches 3. The sun's power peaks astonishingly at 12:00, hitting a maximum of 8, which signifies a high risk for unprotected skin. This intense exposure persists until 14:00, before gradually tapering off through the afternoon. By 15:00, the index drops to 7, then diminishes further to 5 at 16:00, and continues to decline into the evening hours, settling back down to 1 by 19:00. Those planning outdoor activities during the midday hours should take care to protect themselves from the sun’s powerful rays!
| 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 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 8 | 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, UV Index levels undergo significant changes, with notable increases during the warmer months. January and December experience low UV exposure (Index 2), allowing for longer burn times of 45 minutes. However, as early as February, the index rises to 4, indicating a moderate risk with a burn time of 30 minutes. The high-risk months peak from April to August, with UV Index values reaching 8 to 10 and a burn time as brief as 15 minutes—these months are categorized as very high risk for sunburn. In September, UV exposure decreases slightly to a 7, still classified as high risk, necessitating caution with a burn time of 25 minutes. As temperatures drop in October and November, the index falls back to moderate levels, allowing for burn times of 30 minutes. It is crucial for both visitors and residents to take protective measures—such as wearing sunscreen, protective clothing, and seeking shade—particularly during the April to August period, when the risk of skin damage from UV exposure is at its highest.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Merrillan | 2 | 4 | 5 | 8 | 8 | 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 |