Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of South Portland, United States, where exposure to ultraviolet radiation can pose significant risks to skin health and increase the likelihood of sunburn. As a climate zone Dfb area, South Portland experiences a range of UV levels that vary throughout the day, peaking at a high of 9 around midday. Being aware of these fluctuations empowers you to take necessary precautions, ensuring your outdoor activities remain enjoyable and safe while protecting your skin from harmful effects. Stay informed, and enjoy the sun responsibly!
The UV Index for today presents an intriguing journey through the hours. It starts off gently at 1 at 07:00, but as the morning progresses, it climbs swiftly to 2 by 08:00 and reaches a moderate 4 at 09:00. The sun intensifies its rays further, peaking at a robust 9 between 12:00 and 13:00—a reminder to take precautions against harmful UV exposure. Following this peak, the index gradually descends, dipping to 6 at 15:00, and mellowing down to 1 by 18:00. This pattern highlights the importance of seeking shade or applying sunscreen during the midday hours when UV radiation is most potent.
| 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 | 6 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, the UV Index experiences notable fluctuations, influencing both visitor and resident safety. January and December boast a low UV Index of 2, allowing for extended exposure times of 45 minutes without significant risk. However, as we move into spring with February and March, the UV Index rises to 4 and 5 respectively, indicating a moderate risk with a burn time of just 30 minutes. The high-risk months arrive in April through August, with peak values of 9 and 10 during May and June, categorizing the exposure as very high and shortening safe sun exposure to as little as 15 minutes. September sees a slight decrease to a high index of 7, while October and November return to moderate levels. Visitors and residents should take precautionary measures during the higher UV months by seeking shade, wearing protective clothing, and using sunscreen regularly to minimize skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| South Portland | 2 | 4 | 5 | 7 | 9 | 10 | 9 | 8 | 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 |