Last updated: May 3, 2025
Understanding the UV Index in Grafton, United States, is essential for safeguarding your health under the sun. With peak UV levels reaching up to 9 during midday hours, it is crucial to grasp the significance of these measurements for sunburn prevention and overall skin health. Grafton, known for its humid continental climate, presents unique challenges for UV exposure, particularly in the summer months when the sun is at its strongest. By staying informed about the UV Index, residents can take proactive measures to enjoy the outdoors safely while minimizing the risks associated with harmful UV radiation.
As the sun rises, the UV Index gradually climbs, starting at a mild 1 at 07:00. By 08:00, it nudges up to 2, signaling a gentle start to the day. The real intensity kicks in at 09:00, reaching 4, and peaks impressively at 12:00 with a high of 9. The UV levels remain strong throughout the afternoon, holding at 9 until 13:00, before tapering off slightly to 8 at 14:00. By 15:00, it decreases to 7, and as the sun begins its descent, the index drops dramatically, hitting 4 by 16:00 and further declining to a safe 1 by 18:00 and 19:00. Staying sun-safe during the peak hours between 10:00 and 14:00 is essential to protect your skin from harmful UV rays!
| 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 | 9 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits notable seasonal changes throughout the year, with high-risk months primarily occurring from April to August, when the index reaches very high levels (8-10) and a burn time of just 15 minutes is recommended. Specifically, April through July are critical periods, with May and June experiencing the highest values. During these months, it is essential for visitors and residents to take precautions such as wearing sunscreen, protective clothing, and sunglasses, and seeking shade during peak sun hours. Conversely, January and December present lower risks with a UV Index of 2-3, allowing for more extended sun exposure of up to 45 minutes and only moderate protection needed. Overall, staying informed of the UV Index can help ensure safety and enjoyment while outdoors year-round.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grafton | 3 | 5 | 6 | 8 | 9 | 10 | 9 | 9 | 7 | 6 | 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 |