Last updated: May 3, 2025
Understanding the UV Index in Knoxville, United States is crucial for protecting your skin and overall health. With its Cfa climate, characterized by hot summers and mild winters, Knoxville experiences varying UV levels that can significantly impact sun safety. By grasping the UV Index information, residents can better prevent sunburn and long-term skin damage, especially during peak hours when the index skyrockets to 11 around noon. Staying informed about these levels not only enhances your outdoor enjoyment but also safeguards against harmful UV radiation, making it essential for all sun seekers in the area.
As the sun rises on this vibrant day, the UV Index begins its steady ascent. Starting at a mild 1 at 07:00, it quickly climbs to 3 by 09:00, signaling that it’s time to enjoy some outdoor activities with caution. By 10:00, the index reaches a moderate 5, but the real heat kicks in at 11:00, peaking at an intense 11 from 13:00 to 14:00. During this peak, sun protection is crucial, especially for those planning to be outdoors. As the afternoon progresses, the UV Index gently declines, dropping to 7 by 16:00 and tapering off to 4 by 17:00. As the sun sets, the index returns to 1 by 19:00, marking a gentle end to a day of vibrant sunlight.
| 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 | 11 | extreme | 10 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits significant seasonal variation, peaking during the summer months. From January (UV Index 4) to February (UV Index 7), exposure remains moderate to high, with burn times shortening as spring approaches. The months of March and April see a sharp increase in UV levels (9 and 10 respectively), indicating very high risk for sunburn, with a burn time of just 15 minutes. The extreme category dominates from May to August (UV Index 11), where even brief sun exposure can result in burns within 10 minutes. As we move into September and October, the index drops to 10 and 8, maintaining a very high risk, before returning to a moderate level in November and December (UV Index 6 and 4). Visitors and residents are strongly advised to take precautions, especially from March through October, by wearing protective clothing, using sunscreen, and seeking shade during peak sun hours to minimize the risk of skin damage.
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 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Knoxville | 4 | 7 | 9 | 10 | 11 | 11 | 11 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |