Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Chester, United States, where the combination of a BSk climate and varying sun exposure can significantly impact skin health. With UV levels peaking at 9 during the midday hours, awareness of these fluctuations is vital for preventing sunburns and reducing long-term skin damage. By keeping tabs on the UV Index, Chester inhabitants can enjoy the outdoors safely, taking proactive measures when the sun is most intense and securing their skin’s well-being against the potential risks of high UV radiation.
The UV Index reveals a dynamic day of sun exposure, peaking at 9 between 1 PM and 2 PM, indicating a notably high risk of harm from unprotected sun exposure. Early risers find the day starts with a comfortable 1 at 7 AM, gradually rising to 3 by 9 AM. By 11 AM, it reaches 7, encouraging outdoor enthusiasts to take precautions. The intensity continues to climb, soaring to its maximum at noon with an 8, before stabilizing at 9 during the early afternoon. As the sun begins its descent, the UV Index dips to 6 by 4 PM and further decreases to a 3 by 6 PM, finally settling at 1 as night falls. Enjoy the daylight, but remember to shield your skin during those peak hours!
| 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 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences notable seasonal variations. January and December mark the lowest UV levels, categorized as low, with a burn time of 45 minutes. As spring approaches, both February and March see an increase to moderate levels, indicating a burn time of 30 minutes. The UV Index peaks in the summer months of May through August, reaching very high levels (UV Index 8-9) with a significantly reduced burn time of just 15 minutes. As autumn sets in, September returns to a high exposure category, allowing for a 25-minute burn time, while October and November shift back to moderate. Given these fluctuations, it’s crucial for visitors and residents to take precautions during the high-risk months of May through August, including seeking shade, wearing protective clothing, and applying sunscreen to prevent skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chester | 2 | 3 | 5 | 7 | 8 | 9 | 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 |