Last updated: May 3, 2025
Awareness of the UV Index in Grand Coulee, Washington is crucial for safeguarding your skin and overall health. Understanding the daily UV levels helps residents and visitors alike take proactive measures against sunburn and long-term skin damage. With a BSk climate characterized by warm summers and moderate UV exposure, the risk factors peak around midday, especially when the index surges to 8 between noon and 2 PM. By staying informed about UV levels, you can enjoy the beautiful outdoors while effectively protecting yourself from harmful rays.
The UV Index throughout the day reveals a clear trajectory of increasing intensity, peaking at 12:00 PM when it reaches an impressive 8. Starting from a gentle 1 at 7:00 AM, it gradually climbs, hitting 5 by 10:00 AM. The sun’s strength becomes undeniable as it soars to 7 at 11:00 AM and maintains a robust 8 from 12:00 PM to 2:00 PM. As the afternoon progresses, the index drops to 6 by 3:00 PM and continues to decrease, settling back to a mild 1 by 7:00 PM. This hourly data highlights the importance of sun protection during the peak hours when the UV Index is at its highest, particularly from 11:00 AM to 2:00 PM.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | 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 | 6 | high | 25 min |
| 16:00 | 4 | 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 exhibits significant seasonal changes, with high-risk months typically occurring from May to August, when the index peaks at 9, indicating very high exposure levels. During these months, a burn time of only 15 minutes is sufficient to cause skin damage, prompting visitors and residents to take precautions such as wearing sunscreen, hats, and protective clothing. Conversely, the winter months of January and December see low UV levels (index 2) with a burn time of 45 minutes, making outdoor activities less risky. February through April transition to moderate to high levels; thus, it's essential to remain vigilant and adjust sun protection habits accordingly. Always check the UV Index before heading outdoors, particularly in the summer months, to ensure safe and enjoyable outdoor experiences.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Grand Coulee | 2 | 4 | 5 | 6 | 8 | 9 | 9 | 9 | 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 |