Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Saint Johns, United States, where sun exposure can significantly impact your skin health. With peak UV levels reaching up to 10 during midday, it's essential to be aware of the risks associated with sunburn and long-term skin damage. Saint Johns, nestled in a temperate climate zone (Dfb), experiences varying UV exposure throughout the year, making it vital to monitor UV levels regularly. Being informed allows you to take necessary precautions, ensuring safe and enjoyable outdoor activities while protecting your skin from harmful UV radiation.
The UV Index shows a clear trajectory of increasing intensity as the day unfolds. Starting from a mild level of 1 at 7:00 AM, it gradually ascends to 2 by 9:00 AM. The real surge occurs between 10:00 AM and 2:00 PM, peaking at a dangerous 10 at 2:00 PM, indicating a critical need for protection against harmful rays. As the sun begins to descend, the UV Index tapers off, declining to 5 by 5:00 PM, and finally settling back at 1 by 7:00 PM. This data serves as a reminder to stay vigilant under the sun, particularly during those peak hours when UV exposure can be at its highest.
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 1 | low | 45 min |
08:00 | 1 | low | 45 min |
09:00 | 2 | low | 45 min |
10:00 | 4 | moderate | 30 min |
11:00 | 6 | high | 25 min |
12:00 | 8 | very high | 15 min |
13:00 | 9 | very high | 15 min |
14:00 | 10 | very high | 15 min |
15:00 | 9 | very high | 15 min |
16:00 | 7 | high | 25 min |
17:00 | 5 | moderate | 30 min |
18:00 | 3 | moderate | 30 min |
19:00 | 1 | low | 45 min |
As the seasons change, so do UV levels, highlighting periods of higher risk for sun exposure. From January to March, the UV Index remains low to moderate, with February seeing an increase. April to August marks the peak high-risk months, featuring very high UV levels, particularly in June and July, where the burn time drops to a remarkable 15 minutes. September transitions into a high UV category, while October to December see a gradual decline, returning to low risk by year's end. To protect yourself, especially during the high UV months of April through August, it is crucial to wear sunscreen, protective clothing, and seek shade to minimize exposure. Be particularly vigilant during the summer months when burn time is significantly reduced.
UV Risk Categories
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Saint Johns | 2 | 4 | 5 | 8 | 9 | 10 | 10 | 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 |