Last updated: June 2, 2025
In Jonesborough, United States, being aware of the UV Index is crucial for safeguarding your skin against harmful UV radiation. Understanding the daily UV levels can help you prevent sunburn and maintain overall skin health, especially during the summer months when exposure is at its peak. With a Cfa climate, characterized by warm summers and a continental influence, residents face varying UV exposure risks throughout the day. Notably, during peak hours, the UV Index can reach an alarming level of 11, underscoring the importance of taking preventative measures to protect yourself from potential harm.
The UV Index throughout the day reveals a fascinating journey of sun exposure. Starting at a gentle level of 1 at 07:00 and 08:00, the index begins to rise steadily, hitting 3 by 09:00. As the sun reaches its peak, the intensity escalates dramatically, soaring to 10 at noon and peaking at 11 from 13:00 to 14:00—ideal for sun protection measures! The afternoon sees a gradual decline, with values dropping to 9 at 15:00, then further diminishing to 2 by 18:00, and finally settling back at 1 by 19:00. Whether lounging in the sun or engaging in outdoor activities, awareness of this UV landscape is essential for safe enjoyment!
| 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 | 8 | very high | 15 min |
| 12:00 | 10 | 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 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences a significant increase from winter to summer, peaking during the high-risk months of May, June, and July, where it reaches an extreme level of 11 and a burn time of just 10 minutes. As we transition into spring, March and April also show very high levels (UV Index 8 and 10, respectively), resulting in a burn time of 15 minutes. Visitors and residents should be particularly cautious during these months, seeking shade, wearing protective clothing, and applying sunscreen frequently, as exposure can lead to skin damage in a matter of minutes. From August to October, the index gradually decreases; however, September and October still present high risks (UV Index 10 and 8) with a burn time of 15 minutes. As winter arrives, UV levels dip to moderate, and the burn times increase to 30 minutes in November and December, suggesting a lower risk of UV exposure. Always prioritize sun safety, especially in the warmer months.
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 |
| Jonesborough | 4 | 6 | 8 | 10 | 11 | 11 | 11 | 10 | 10 | 8 | 5 | 3 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |