Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Santa Rosa, United States, where sun exposure can lead to significant health risks. High UV levels, particularly between late morning and early afternoon, can cause painful sunburns and increase the risk of long-term skin damage. With Santa Rosa's BSk climate, characterized by dry summers and moderate temperatures, the potential for intense solar radiation is notable, particularly during peak hours when the UV index often reaches levels of 10 to 13. By staying informed about current UV conditions, you can take proactive steps to protect your skin and enjoy the beautiful California sun safely.
At dawn, the UV Index begins at a mild level of 1 by 7:00 AM, offering a safe start to the day. As the sun climbs higher, it ascends rapidly; by 10:00 AM, the index hits a more intense 7. The peak arrives at 12:00 PM, reaching a striking 12, prompting outdoor enthusiasts to seek shade and protect their skin. This intensity remains high, with a max of 13 at 1:00 PM. As afternoon rolls in, a gradual decline commences; by 3:00 PM, it's at 9, and continues to drop to 4 by 5:00 PM, ensuring a more comfortable evening. By 7:00 PM, the UV Index settles back to a safe 1, marking the day's end for sun exposure.
| 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 | 13 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 7 | 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 |