Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors of Fort Irwin, United States, especially given its warm BWk climate. High UV levels, particularly between 10 AM and 3 PM, can lead to severe sunburn and long-term skin health issues if precautions are not taken. With peak UV Index values reaching as high as 12 during midday, awareness can empower individuals to make informed decisions about sun safety, protecting themselves from the sun's harmful rays. Stay vigilant and ensure your outdoor activities are coupled with effective sun protection!
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 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 |