Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Chelsea, United States, as it provides essential information about the potential risks of ultraviolet (UV) radiation exposure throughout the day. By being aware of UV levels, you can take proactive steps to prevent sunburn and protect your long-term skin health. Chelsea, located in a Dfb climate zone, experiences significant UV radiation, particularly during midday hours when the index peaks at a high of 10. Recognizing these patterns not only helps you enjoy the sun safely but also contributes to maintaining healthier skin in the face of varying weather conditions.
The hourly UV Index data reveals a dynamic shift in sun intensity throughout the day, starting from a gentle 1 at 07:00, ideal for morning strolls. As the sun rises higher, the index escalates, peaking at a potent 10 between 12:00 and 13:00. This mid-day surge emphasizes the need for sunscreen and protective gear, as the risk of harm from UV rays increases significantly. By 15:00, the index begins to decline, settling at 7 before tapering off further to a mere 1 by 19:00, signaling a safe reprieve for evening outdoor activities. Stay aware and protect 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 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | 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 demonstrates significant seasonal changes, particularly peaking in the summer months. Notably, April to August presents the highest risk for UV exposure, with May and June reaching a maximum of 10, categorized as very high risk, where the burn time drops to just 15 minutes. Visitors and residents should be especially cautious during these months, ensuring they wear protective clothing, apply broad-spectrum sunscreen, and seek shade during peak hours. Conversely, the UV Index declines from September onwards, dropping to a low of 2 in December, which indicates reduced risk. It is advisable to remain vigilant year-round, adapting sun safety practices according to the current UV levels to ensure optimal skin protection.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chelsea | 3 | 5 | 5 | 8 | 9 | 10 | 9 | 9 | 7 | 6 | 4 | 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 |