Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Sumas, United States, where the climate features cool, temperate seasons. Awareness of UV levels is vital not only for preventing painful sunburns but also for protecting skin health in the long run. With peak UV readings reaching 8—indicating a high risk of harm from unprotected sun exposure—it's essential to stay informed and prepared. In Sumas, where the sun can be deceptively potent even in cooler weather, knowing when UV levels rise can make all the difference in maintaining your well-being.
As the sun rises, the UV Index begins its ascent, starting at a gentle 1 at 07:00. By 09:00, it gradually ramps up to 3, signaling the start of a moderately sunny day. The index peaks at 8 from 12:00 to 14:00, reminding everyone to take care as midday rays can be intense. Following this peak, the UV levels begin to decline sharply, dropping to 7 at 15:00 and further to 4 by 17:00. As the sun sets, the UV Index falls back to 2 at 18:00 and settles at 1 by 19:00, marking the end of the day’s solar intensity. Stay sun-safe and enjoy the rays while they last!
| 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 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | 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 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index reflects significant seasonal changes that impact sun exposure and potential skin damage. The high-risk months are from April to August, where the UV Index peaks at 9 in July, indicating very high exposure risk with a burn time as low as 15 minutes. Visitors and residents are advised to take extra precautions during these months, including wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade during peak sun hours. Meanwhile, the winter months of January and February see a drop in UV levels to 2 and 3, classified as low to moderate, allowing for more lenient sun exposure while still taking care to protect skin. As the UV Index generally decreases towards the end of the year, exposure caution can be relaxed, particularly in November and December when burn times extend back to 45 minutes.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sumas | 2 | 3 | 5 | 6 | 7 | 8 | 9 | 8 | 6 | 4 | 2 | 1 |
| 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 |