Last updated: June 2, 2025
Understanding the UV Index is vital for residents of Santa Clara, California, where the combination of a mild, Mediterranean climate and high sun exposure can lead to significant UV radiation levels. With summer months experiencing peaks in the UV Index—reaching a maximum of 11 during midday hours—it's crucial to be aware of the risks associated with prolonged sun exposure. Protecting your skin from sunburn, premature aging, and long-term health issues starts with monitoring these UV levels. By knowing when to seek shade or apply sunscreen, you can enjoy the beautiful sunny days in Santa Clara while keeping your skin healthy and safe.
The UV Index today paints a vivid picture of solar intensity, peaking dramatically between 12:00 PM and 2:00 PM with a striking 11—a warning to seek shade and protect skin. Starting the day at a gentle 1 at 7:00 AM, the index gradually climbs, reaching 4 by 9:00 AM and escalating to 9 by 11:00 AM. As the sun reaches its zenith, the index hits 11, indicating extreme conditions that persist for a solid three hours. Following this midday blast, it gracefully declines to 6 by 4:00 PM, before tapering off to a safer 1 by the evening. Remember to stay sun-smart during those peak hours!
| 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 | 6 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | 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, with the highest risk occurring during the late spring and summer months. March marks the start of increased UV intensity, reaching 8, categorizing it as very high, while April sees a further rise to 9. The peak UV index of 11, indicating an extreme exposure category, occurs from May to July, with the shortest burn time of just 10 minutes. As summer wanes, August and September still reflect high UV levels of 10 and 9, respectively. In contrast, January, November, and December are characterized by lower UV indices of 4, 5, and 3, which fall into the moderate category, allowing for longer safe exposure times of 30 minutes and 25 minutes in October. Visitors and residents are advised to take extra precautions, particularly from March through September when UV levels are at their most hazardous, including wearing sunscreen, protective clothing, and seeking shade during peak 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 |
| Santa Clara | 4 | 5 | 8 | 9 | 11 | 11 | 11 | 10 | 9 | 7 | 5 | 3 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |