Last updated: July 2, 2025
Understanding the UV Index in Grand Coulee, United States, is crucial for protecting your skin and maintaining overall health. With typical UV exposure peaking around noon, when levels can reach as high as 9, awareness of UV ratings can help you prevent sunburn and long-term skin damage. Grand Coulee's semi-arid climate often results in bright sunny days that can quickly intensify UV radiation. By tracking those UV levels daily, you can take necessary precautions to enjoy the outdoors safely!
The UV Index for the day begins low at 1 by 7:00 AM, gradually rising as the sun climbs higher in the sky. By 9:00 AM, it reaches 4, marking a noticeable increase. The intensity peaks at 12:00 PM with a scorching 9, maintaining this high level until 14:00 PM. As the afternoon progresses, the index dips to 7 at 15:00 PM, and then continues its descent to 4 by 17:00 PM. The sun’s waning effects are apparent by the evening, with the UV Index dropping to 1 by 19:00 PM. This day highlights the importance of sun protection during peak hours when the index hits its maximum.
| 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 | 6 | high | 25 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 4 | 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 |