Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Saint Johnsbury, where the combination of a humid continental climate (Dfb) and varying sun exposure can heighten the risk of harmful effects from ultraviolet radiation. With peak UV levels reaching as high as 9 during midday, awareness of these levels is essential for effective sunburn prevention and maintaining long-term skin health. Whether it's enjoying outdoor activities or simply basking in the sun, knowing the UV Index can help you take necessary precautions to protect yourself and your loved ones from potential skin damage all year round.
The UV Index today presents a notable climb as the sun ascends, peaking at 9 around noon and early afternoon, signaling very high sun exposure risk. Starting gently at 1 by 7 AM, the index rises steadily, reaching 6 by 10 AM and then surging to its maximum of 9 between 12 PM and 1 PM. Early afternoon brings a slight decline to 8 at 2 PM, followed by a gradual decrease through the later hours, settling back to 1 by 7 PM. With this trajectory, it's crucial to take precautions during the peak hours of 11 AM to 1 PM, ensuring skin protection against harmful UV rays. Stay safe and enjoy the sun wisely!
| 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 | 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, the UV Index experiences noticeable fluctuations, impacting the risk of skin damage due to sun exposure. High-risk months are primarily from April to August, where the UV Index reaches very high levels of 8 to 10, necessitating caution with a significantly reduced burn time of just 15 minutes. In contrast, the UV levels are much lower from January to March and again from November to December, characterized by low to moderate exposure with burn times extending up to 45 minutes. Residents and visitors should be particularly mindful during the peak summer months, ensuring adequate sun protection such as sunscreen, hats, and clothing, and seeking shade during the day to minimize the risk of skin damage. Remember, smarter sun habits can help you enjoy the outdoors safely!
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Saint Johnsbury | 2 | 4 | 5 | 8 | 9 | 10 | 9 | 9 | 7 | 5 | 3 | 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 |