Last updated: May 3, 2025
Understanding the UV Index is essential for residents of Lancaster, United States, as it plays a crucial role in sunburn prevention and overall skin health. By being aware of UV levels, you can take proactive measures to protect yourself from harmful sun exposure, particularly during those peak hours when the index soars to levels 10. Lancaster’s Cfa climate brings warm summers with significant UV exposure risks, making it all the more important to stay informed. Armed with this knowledge, you can enjoy your time outdoors while minimizing the chances of skin damage.
The UV Index offers a clear snapshot of sun intensity throughout the day. Starting off gently, the morning hours (07:00 and 08:00) register a modest index of 1, making it safe to enjoy some outdoor activities. As the day progresses, the sun’s rays ramp up, peaking at 10 from 12:00 to 14:00—the ideal time for sun safety reminders. The UV Index then gradually declines, showcasing a friendly 8 at 15:00 before tapering down to 4, 2, and finally 1 by the evening hours. As such, it's crucial to stay vigilant around midday and seek shade while enjoying the outdoors.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 10 | 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index values fluctuate significantly, indicating varying levels of sun exposure risk. January and December see moderate UV levels (Index 4), allowing for up to 30 minutes of safe sun exposure. As spring arrives, the risk increases sharply; February (Index 6) marks the beginning of high-risk months with a burn time of 25 minutes, escalating to very high levels in March and April (Index 8-10), where you should limit exposure to 15 minutes. The peak months for UV intensity occur in June and July, classified as extreme (Index 11), requiring careful sun protection measures within just 10 minutes. As summer fades, the UV Index remains high in August, then gradually decreases through September and October (Index 9-8, with 15 minutes burn time), before returning to high in November (Index 6, 25 minutes). Residents and visitors should prioritize sun protection, especially from March to August, ensuring to wear sunscreen, hats, and protective clothing during peak UV hours.
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 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Lancaster | 4 | 6 | 8 | 10 | 10 | 11 | 11 | 10 | 9 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |