Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of San Dimas, United States, a charming spot in a Mediterranean climate zone that experiences varying UV exposure throughout the day. With peak UV levels reaching 11 in the late morning and early afternoon, awareness of these levels is vital for effective sunburn prevention and maintaining skin health. By recognizing when UV radiation is most intense, locals can take proactive measures to protect themselves from harmful effects, ensuring that sunny days can be enjoyed safely while minimizing the risks associated with overexposure.
At dawn, the UV Index starts at a gentle 1 by 07:00, indicating minimal exposure risk. As the sun climbs higher, the intensity rises sharply, reaching a maximum of 11 between 12:00 and 13:00—a time when protective measures are crucial. The peak UV Index highlights the importance of sun safety, as conditions can be particularly harsh. The afternoon sees a gradual decline, dipping to 8 by 15:00 and further decreasing to 3 by 17:00. As evening approaches, the index wanes to a mellow 1 by 19:00, suggesting a return to safer exposure levels. Keep in mind that tracking the UV Index throughout the day can help protect your skin from harmful rays!
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 | 7 | high | 25 min |
11:00 | 9 | very high | 15 min |
12:00 | 11 | extreme | 10 min |
13:00 | 11 | extreme | 10 min |
14:00 | 10 | very high | 15 min |
15:00 | 8 | very high | 15 min |
16:00 | 6 | high | 25 min |
17:00 | 3 | moderate | 30 min |
18:00 | 2 | low | 45 min |
19:00 | 1 | low | 45 min |
During the year, UV Index values show significant seasonal variation, peaking in the summer months. High-risk months for UV exposure include March through August, particularly notable in June and July, where the UV Index reaches an extreme level of 12 and 11, respectively, with a burn time of only 10 minutes. Visitors and residents are advised to take necessary precautions during these months, such as wearing protective clothing, using broad-spectrum sunscreen, and limiting sun exposure, especially between 10 AM and 4 PM. As UV levels decrease from September onward, with moderate levels returning in the winter months of November and December, maintaining sun safety remains important, especially during high-exposure periods.
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 |
San Dimas | 4 | 6 | 8 | 10 | 10 | 12 | 11 | 10 | 10 | 7 | 5 | 4 |
Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |