Last updated: June 2, 2025
In Walnut Creek, United States, being aware of the UV Index is crucial for protecting your skin and overall health. Understanding UV levels is essential to prevent sunburn and minimize the risk of skin damage, especially during the peak hours when levels can soar. With a BWk climate, residents and visitors face unique exposure risks, particularly around midday when the UV Index can reach a high of 12. This highlights the importance of staying informed and taking proactive measures to safeguard against harmful UV rays while enjoying the beautiful California sunshine.
The UV Index varies significantly throughout the day, peaking from 12:00 PM to 1:00 PM with a striking 12. Early morning starts off mild, reaching a maximum of 1 at 7:00 AM before climbing through the hours. At 9:00 AM, it hits 5, and by 10:00 AM, it intensifies to 8. The sun's intensity continues to rise, attaining its highest points at 11:00 AM and 12:00 PM, with the index hitting 10 and 12, respectively. As the afternoon progresses, a gradual decline begins; by 3:00 PM, it dips to 8, then further to 5 at 4:00 PM. The UV Index settles back down to 3 by 5:00 PM and returns to 1 as evening approaches, illustrating the importance of sun protection, particularly during the peak hours of midday.
| 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 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 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 |