Last updated: June 2, 2025
Understanding the UV Index is crucial for everyone in Joshua Tree, where the sun’s intense rays can pose significant risks to skin health. With a climate classified as BWk, the region experiences notably high UV levels, particularly during peak hours; for instance, the UV Index soars to a maximum of 12 from noon to 1 PM, indicating extreme risks of harm from unprotected sun exposure. By staying informed about UV levels, you can effectively prevent sunburns and maintain skin integrity, making it essential to check the UV Index before heading out into the stunning desert landscape. Whether you're hiking amidst the iconic Joshua Trees or simply enjoying the sun, awareness is your first line of defense against harmful UV radiation.
The UV Index starts off gently at 1 by 7:00 AM, making it a safe time for morning activities. As the day progresses, the index climbs steadily, reaching 3 by 8:00 AM, and 5 by 9:00 AM, indicating a need for some sun protection. The intensity peaks at 12:00 PM with a striking 12, marking the highest risk period between 11:00 AM and 1:00 PM, where applying sunscreen is crucial to avoid harm. The afternoon sees a gradual decline, as the index drops to 11 by 2:00 PM and slides to 9 by 3:00 PM. As the sun begins its descent, the UV Index continues to lessen, landing at 3 by 5:00 PM and settling back to a comfortable 1 by 7:00 PM. Remember to stay sun-safe during the midday hours when the UV levels are at their peak!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 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 | 9 | 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 |
Throughout the year, the UV Index fluctuates significantly, impacting how residents and visitors should approach sun safety. From March through August, the UV Index reaches its peak, with high-risk months identified as April, May, June, July, and August, where it remains in the extreme category, necessitating protective measures with a burn time of only 10 minutes. As summer transitions to fall, the UV Index begins to decline, though September and October still present very high exposure risks with burn times of 15 minutes. In contrast, the winter months of January, November, and December have a moderate UV Index, allowing for longer burn times of 30 minutes. Visitors and residents are advised to limit sun exposure, particularly during peak hours in high-risk months, and to use sunscreen, protective clothing, and sunglasses to safeguard against harmful UV rays.
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 |
| Joshua Tree | 4 | 6 | 9 | 11 | 12 | 12 | 13 | 11 | 10 | 8 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |