Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors of Joint Base Lewis McChord, where the combination of a Csb climate and varying sunlight levels can significantly impact skin health. The UV Index indicates the strength of ultraviolet radiation, and being aware of these levels can help prevent sunburn and long-term skin damage. With peak UV exposure reaching 8 during midday hours, it’s essential to take proactive measures to protect yourself from harmful rays. This awareness not only enhances your outdoor enjoyment but also ensures your skin remains healthy under the Pacific Northwest sun.
The UV index throughout the day reveals a fascinating pattern of sun intensity. Early risers will notice a gentle start at 1 around 7:00 AM, gradually climbing to a moderate 3 by 9:00 AM. As the sun reaches its peak, the index hits 6 at 11:00 AM, escalating to an impressive 8 from 12:00 PM to 2:00 PM—the height of solar exposure. After this, the UV levels begin to wane, dropping to 7 at 3:00 PM, and further decreasing to moderate numbers of 5, 3, and 2 as the sun sets, concluding the day with a calm 1 at 7:00 PM. Remember, during the peak hours, sun safety is crucial!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 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 markedly, with high-risk months typically occurring from April to August. During this period, the UV Index regularly reaches very high levels, particularly in May, June, and July, where a burn time of just 15 minutes indicates an increased risk of skin damage. As the year transitions towards autumn and winter, the UV Index drops to moderate and then low, with safer exposure times of 30 to 45 minutes in effect during the colder months. Visitors and residents are advised to take precautions during the high-risk months by wearing sunscreen, protective clothing, and seeking shade, especially during midday hours when the sun's rays are strongest. Staying informed about the daily UV Index can help ensure safe and enjoyable outdoor activities year-round.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Joint Base Lewis McChord | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 7 | 5 | 3 | 2 |
| 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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |