Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Walnut Creek, California, where sunny skies and a warm, semi-arid climate contribute to high levels of ultraviolet radiation. Recognizing UV levels can significantly aid in sunburn prevention and overall skin health by helping you make informed choices about outdoor activities. With a peak index reaching 11 during midday, Walnut Creek experiences notable UV exposure risks, particularly from late morning to early afternoon. By staying aware of the UV Index, you can protect your skin and enjoy the beautiful California weather safely!
The UV Index begins the day at a gentle 1 at 7:00 AM, ideal for early risers enjoying the outdoors. As the sun climbs, the index steadily rises, reaching 3 by 8:00 AM and hitting 5 at 9:00 AM. It's 10:00 AM when things heat up, peaking at a striking 11 by noon, making it crucial to take precautions. The UV Index holds steady at this maximum of 11 from 1:00 PM to 2:00 PM, signaling extreme exposure levels. Following this hour, conditions begin to cool down with a decline to 9 by 2:00 PM and tapering to 4 by 4:00 PM. As the day winds down, the index drops sharply to 1 by 6:00 PM, providing a gentle close to the day's UV exposure. Adapting outdoor activities in line with these UV fluctuations is essential for skin health!
| 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 | 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 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index displays significant seasonal variations. The high-risk months, characterized by extreme UV levels and minimal burn times, are May through August, with June and July reaching a peak UV Index of 12 and an urgent burn time of just 10 minutes. As spring transitions to summer, the UV Index escalates from a moderate level of 4 in January to an extreme of 11 in May, then gradually declines again in fall and winter. Visitors and residents are advised to take precautions during these high-risk months, such as seeking shade, wearing protective clothing, and applying broad-spectrum sunscreen to minimize the risks of skin damage from UV exposure. In contrast, during the moderate months of November and December, exposure is less critical, but protective measures are still recommended. Stay informed and protect your skin year-round!
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 |
| Walnut Creek | 4 | 6 | 8 | 10 | 11 | 12 | 12 | 11 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |