Last updated: May 3, 2025
Understanding the UV Index is crucial for anyone spending time in Joshua Tree, where the arid desert climate can lead to significant sun exposure. With UV levels often peaking at a staggering 12 during midday hours, being aware of these readings is essential for preventing sunburn and promoting long-term skin health. In this stunning but challenging environment, where clear skies and high altitudes result in increased UV radiation, safeguarding your skin by knowing when to seek shade or wear protective gear is more important than ever. Stay informed, stay safe, and enjoy all that Joshua Tree has to offer!
The UV Index varies significantly throughout the day, peaking from 12:00 PM to 1:00 PM with a striking 12. Early morning starts off mild, reaching a maximum of 1 at 7:00 AM before climbing through the hours. At 9:00 AM, it hits 5, and by 10:00 AM, it intensifies to 8. The sun's intensity continues to rise, attaining its highest points at 11:00 AM and 12:00 PM, with the index hitting 10 and 12, respectively. As the afternoon progresses, a gradual decline begins; by 3:00 PM, it dips to 8, then further to 5 at 4:00 PM. The UV Index settles back down to 3 by 5:00 PM and returns to 1 as evening approaches, illustrating the importance of sun protection, particularly during the peak hours of midday.
| 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 | 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 |
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 |