Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Lancaster, United States, as it provides essential insights into the levels of ultraviolet radiation present throughout the day. Being aware of UV levels is key to preventing sunburn and protecting skin health, particularly during peak hours when the index reaches 10 around noon. With Lancaster's Dfa climate, known for its four distinct seasons, the risks of UV exposure can fluctuate significantly, making it important for locals to stay informed and take appropriate precautions to safeguard their skin year-round.
The UV Index throughout the day presents a dynamic picture of solar intensity. Morning hours start gently, with a low of 1 at 07:00 and a gradual rise to 2 by 08:00. As the sun climbs higher, the index peaks at a striking 10 at 13:00, signaling the most intense sun exposure, making it prudent for sun protection. From 14:00, the UV Index begins to dip, yet remains significant at 9, before tapering off to 5 by 16:00. As evening approaches, the levels drop further, resting at 1 by 19:00. This hourly progression showcases the importance of sun safety measures, particularly during those midday hours when the UV radiation is at its highest.
| 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 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 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 exhibits significant seasonal variations, with high-risk months occurring from April to August. During this period, the UV Index peaks at 11, categorized as extreme in June and July, meaning visitors and residents should take extra precautions. Notably, April and May also pose high risks with very high ratings of 9 and 10, respectively. As a guideline, those spending time outdoors should limit sun exposure during these months, particularly between 10 AM and 4 PM, when UV rays are most intense. It’s advisable to wear protective clothing, apply broad-spectrum sunscreen, and seek shade to minimize the risk of skin damage. As we transition into the fall and winter months, UV levels decrease, with December presenting a much lower risk. However, even in moderate months like January and February, some sun protection remains necessary for prolonged outdoor activities.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
| Lancaster | 3 | 5 | 6 | 9 | 10 | 11 | 11 | 10 | 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 |