Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Knoxville, United States, where sunny days are abundant and outdoor activities are popular. The UV Index provides vital information on the strength of ultraviolet radiation, helping you make informed decisions to prevent sunburn and protect your skin health. With a Dfb climate, Knoxville experiences significant UV exposure, especially during the summer months when indices can soar to 10 around midday. By staying aware of the UV levels, you can enjoy the beautiful Knoxville outdoors while safeguarding your skin from harmful rays.
As the sun rises, the UV Index begins its ascent, peaking at an invigorating 10 by 1:00 PM. Early morning, from 7:00 AM to 8:00 AM, sees a mild 1 to 2, making it a perfect time for a leisurely stroll. By 9:00 AM, the UV Index reaches 3, signaling a need for some sun protection. The real intensity kicks in around 11:00 AM, hitting 8, and just after noon, it soars to its daily maximum of 9. The afternoon hours see a slight decline, with values tapering from 9 at 2:00 PM to 6 by 4:00 PM. As daylight wanes, the UV Index gently drops to 1 by 7:00 PM, wrapping up a day of vibrant sunlight but reminding us to stay vigilant during those peak hours. Remember to reapply sunscreen and seek shade to keep safe while enjoying those sunny moments!
| 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 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | 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 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, peaking during late spring and summer months. High-risk months for UV exposure are April through September, where the UV Index frequently reaches levels classified as very high; particularly notable are May, June, and July, when it consistently hits a maximum of 10. Visitors and residents are advised to take precautions during these months, with burn times dramatically reduced to as little as 15 minutes. In contrast, January, February, and November present moderate UV levels, and December has a low index, making sun safety measures less critical during these months. To protect against skin damage, it is essential to wear sunscreen, seek shade, and wear protective clothing, especially between peak months of April and September.
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 |
| Knoxville | 3 | 5 | 6 | 9 | 10 | 10 | 10 | 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 |