Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Santa Rosa, United States, as it serves as a guide to safeguarding your skin against the harmful effects of ultraviolet radiation. Awareness of UV levels is vital for preventing sunburns and promoting long-term skin health, especially in a region with a dry, warm climate typical of a BWh zone. During the peak hours of sunlight, particularly between 10 AM and 2 PM, the UV Index can soar to intense levels, reaching a maximum of 12, indicating a high risk for harm without appropriate protection. By staying informed about the UV Index, you can enjoy Santa Rosa’s sunny days while keeping your skin safe from potential damage.
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 |
The UV Index demonstrates significant seasonal variations, with the highest risk months occurring from March to August, when the index reaches extreme levels of 11 to 12 and the burn time plummets to 10 minutes. April and May are particularly critical with a peak UV Index of 12, indicating that individuals should exercise extreme caution during outdoor activities. Conversely, January and December present lower UV exposures, categorized as moderate, allowing a safer burn time of 30 minutes. Visitors and residents should be particularly vigilant during the spring and summer months, ensuring they wear appropriate sun protection, seek shade during peak hours, and limit their sun exposure to minimize the risk of UV-related health issues.
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 |
| Santa Rosa | 5 | 7 | 9 | 11 | 12 | 12 | 12 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |