Last updated: July 2, 2025
Staying informed about the UV Index is essential for residents and visitors in Keystone, United States. Understanding the levels of UV radiation helps you protect yourself from harmful sun exposure, preventing sunburn and promoting long-term skin health. With Keystone's Dfa climate, characterized by a mix of warm summers and cooler winters, UV exposure can peak significantly during midday hours, making it crucial to stay aware of those rising numbers. Protect your skin and enjoy the beautiful outdoors by knowing when to seek shade or apply sunscreen!
The UV Index today reveals a clear pattern of solar intensity peaking as the day progresses. Starting at a low 1 at 07:00, it steadily climbs to 2 by 08:00 and further to 3 by 09:00. The sun asserts its dominance with a 6 at 10:00, escalating dramatically to 8 at 11:00. The intensity reaches its zenith with a staggering 10 from 13:00 to 14:00, the point at which sun safety becomes crucial. As the afternoon wears on, the index begins to taper off, dropping to 8 at 15:00, and further cooling to 4 by 17:00. The evening ushers in a return to more manageable levels, with 2 at 18:00 and winding down to 1 by 19:00. Plan your outdoor activities wisely, savoring the sun's rays during the peak hours while taking precautions to protect your skin!
| 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 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | 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, the UV Index exhibits notable fluctuations, with high-risk months typically falling between April and September. During this period, the UV Index peaks in June at a severe level of 11, signifying an extreme exposure category with a burn time of just 10 minutes. Following closely are May and July, both rated as very high with indices of 9 and 10 respectively, while April and August maintain a very high category as well, with indices reaching 8. As winter approaches, the UV Index drops to a moderate level in January, February, November, and December, offering safer exposure times of up to 30 minutes. To protect yourself during peak UV times, especially from April to September, it's crucial to apply sunscreen regularly, wear protective clothing, and limit sun exposure during mid-day 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 |
| Keystone | 3 | 5 | 6 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 3 | 3 |
| 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 |