Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Fort Irwin, United States, where the sun-soaked BWk climate can lead to significant UV exposure risks. As the sun reaches its peak, with UV levels soaring to 11 between noon and 1 PM, awareness of these values is vital for preventing sunburn and promoting overall skin health. By grasping the daily fluctuations in UV intensity, individuals can make informed decisions to protect themselves and enjoy the stunning desert environment safely.
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 |
Throughout the year, the UV Index experiences significant fluctuations, with the highest levels occurring from March to August. March and April both exhibit a very high UV Index of 9 and 10, respectively, leading to a burn time of only 15 minutes. The peak months, May and June, are classified as extreme with a UV Index of 11 and 12, necessitating caution as the burn time reduces to just 10 minutes. July and August continue this trend, remaining in the extreme category, before a gradual decline in September to 10 (very high) and further down to high with an Index of 7 in October. The year wraps up with moderate levels in November and December, where the burn time increases to 30 minutes. Given these variations, residents and visitors should take extra precautions from March through October, particularly during May and June, by wearing protective clothing, applying high-SPF sunscreen, and seeking shade to minimize their risk of sunburn and long-term skin damage.
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 |
| Fort Irwin | 4 | 6 | 9 | 10 | 11 | 12 | 12 | 11 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |