Last updated: July 2, 2025
Understanding the UV Index in Santa Rosa is crucial for protecting your skin and overall health from harmful ultraviolet radiation. With the sun's intensity peaking during the midday hours, staying informed about UV levels can help you take necessary precautions to prevent sunburn and long-term skin damage. Given Santa Rosa's BSk climate, where sunny days are common, residents and visitors alike face increased risks of UV exposure, particularly between 10 AM and 2 PM when the index can reach as high as 12. By being aware of the UV Index, you can enjoy the beautiful outdoors while safeguarding your skin's health.
At sunrise, the UV Index begins its steady climb, starting at a safe 1 at 07:00. As the morning progresses, it escalates to 2 by 08:00 and reaches a pleasant 4 by 09:00. However, the real intensity hits between 10:00 and 13:00, with the UV Index peaking at a scorching 12 at 12:00, indicating a high risk of harm from unprotected sun exposure. As the afternoon unfolds, levels gradually descend, hitting 9 at 15:00 before tapering off to 4 by 17:00. By the evening hours, the index returns to a mild 1 by 19:00, reminding us of the importance of sunscreen amidst the sun's powerful midday 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 | 10 | very high | 15 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, peaking during late spring and summer months. January sees a moderate UV Index of 4, allowing for a burn time of 30 minutes, while February reaches a high index of 7 with a burn time of just 25 minutes. As March arrives, the index escalates to 9, classified as very high, with a notably reduced burn time of 15 minutes. The situation becomes critical from April to September, where the UV Index remains at an extreme level of 11 to 13, and the burn time drops to just 10 minutes. October marks a slight reduction in risk with a UV Index of 8 and a burn time of 15 minutes. Finally, November and December revert to moderate levels, with indices of 5 and 4, respectively. Visitors and residents are strongly advised to take precautions during high-risk months—particularly from March through October—by wearing protective clothing, applying sunscreen regularly, and limiting sun exposure, especially during peak midday hours.
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 | 4 | 7 | 9 | 11 | 12 | 13 | 12 | 12 | 11 | 8 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |