Last updated: June 2, 2025
Understanding the UV Index in Lake Arrowhead is crucial for protecting your skin and overall health. As a popular destination nestled in the San Bernardino Mountains, this region boasts beautiful sunny days and outdoor activities, making awareness of UV levels even more important. The UV Index can peak at 12 during midday, indicating a high risk of harm from unprotected sun exposure, especially for those engaging in hiking or water sports. By being informed about UV levels, you can take proactive measures to prevent sunburn and long-term skin damage, ensuring you enjoy Lake Arrowhead’s stunning scenery safely and healthily.
As the sun rises, the UV Index begins its ascent, starting at a gentle 1 by 7:00 AM. By 9:00 AM, it reaches a moderate 5, but soon after, the intensity peaks. At 11:00 AM, the index hits 10, and by noon, it soars to a scorching 12, indicating a high risk of harm from unprotected sun exposure. The afternoon maintains this intensity, with the index remaining steady at 12 until 1:00 PM, before gradually declining. By 3:00 PM, it starts its descent to 8, then dips further to 6 by 4:00 PM, and settles back to a safer 2 by 6:00 PM. As the sun begins to set, the evening returns to a minimal 1 by 7:00 PM, reminding us to enjoy the daytime sun responsibly.
| 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 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | 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 |