Last updated: May 3, 2025
In Lake Arrowhead, United States, being aware of the UV Index is crucial for protecting your skin and overall health. Understanding UV levels can help you prevent painful sunburns and reduce the long-term risks of skin damage. Nestled in a picturesque Csa climate, Lake Arrowhead experiences significant UV exposure, particularly during midday hours when the index peaks at 11. This means that outdoor enthusiasts should stay informed and take necessary precautions to shield themselves from harmful ultraviolet rays.
At dawn, the UV Index begins its ascent with a mild 1 at 7:00 AM, gradually increasing to a moderate 2 by 8:00 AM. As the sun climbs higher, it reaches a noteworthy 5 at 9:00 AM, but the real intensity hits at 10:00 AM with a strong 7. By 11:00 AM, the UV levels soar to a peak of 10, continuing at an impressive 11 from 12:00 PM to 1:00 PM—the highest of the day. After this midday intensity, the numbers begin to wane, dropping to 10 at 2:00 PM, then to 8 at 3:00 PM. The afternoon cools off slightly, falling to 5 by 4:00 PM, and ultimately settling back to 3 by 5:00 PM. As the day draws to a close, the UV Index gently slips to 1 by 6:00 PM, and remains there until 7:00 PM, indicating a safe return to evening activities.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | 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 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences significant seasonal variation, peaking between March and August when exposure levels reach extreme categories. Notably, April, May, and June have the highest readings at 11 and 12, indicating a burn time as short as 10 minutes during these months. Visitors and residents should be particularly cautious from March to August, with March and April marking the onset of these high-risk months. During this time, it is advisable to wear protective clothing, apply sunscreen frequently, and seek shade whenever possible, especially during midday hours. As fall approaches, the UV Index begins to decline, offering slightly safer conditions in October and November, yet vigilance is still recommended during these months with moderate exposure.
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 |
| Lake Arrowhead | 4 | 6 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 8 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |