Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Knottsville, United States, where the climate features warm summers and moderate UV exposure. Being aware of UV levels can help you safeguard your skin against sunburn and reduce long-term health risks such as skin cancer. In Knottsville, UV indices can reach a peak of 11 during midday hours, emphasizing the need for sun protection during the hottest parts of the day. With the average high temperatures and sun exposure common in a Cfa climate, staying informed will enable you to enjoy the outdoors while prioritizing your skin's health.
The UV Index throughout the day follows a dynamic trajectory, peaking during midday hours. Early in the morning, at 7:00 AM, the index is a mere 1, indicating minimal risk. However, as the sun rises, the intensity escalates sharply, reaching 11 by 12:00 PM and 1:00 PM, signaling a high risk period for unprotected skin. By 3:00 PM, there's a noticeable decline to 8, and it continues to fall gently, arriving back at 1 by 7:00 PM. It’s crucial to stay protected during those peak hours, especially between 10:00 AM and 3:00 PM, when the sun's rays are the strongest.
| 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 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | 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 |
Throughout the year, UV index levels display significant seasonal variation, with notable peaks during the spring and summer months. From January (UV Index 3) to March (UV Index 7), exposure remains moderate to high, but by April and May (UV Index 10), it escalates to a very high category, necessitating increased sun protection. The most critical periods, with an extreme UV index of 11, occur in June, reminding visitors and residents to exercise extreme caution and limit sun exposure to just 10 minutes. This trend continues into July and August with very high levels, tapering off slightly in September (UV Index 9), before returning to high levels in October (UV Index 7). Residents and visitors should prioritize sun safety during the high-risk months of April to September, using sunscreen, wearing protective clothing, and seeking shade to minimize UV exposure. In contrast, November and December see a welcome decrease with a moderate UV index, allowing for more comfortable outdoor activities.
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 |
| Knottsville | 3 | 6 | 7 | 10 | 10 | 11 | 10 | 10 | 9 | 7 | 5 | 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 |