Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Mountain View, United States, as it provides essential information about the sun's ultraviolet radiation levels and their potential impact on skin health. With peak UV levels reaching 11 during midday, awareness of these fluctuations helps in effective sunburn prevention and reduces the risk of long-term skin damage. Mountain View's climate, characterized by its Dfb zone, offers ample sunshine, making it important for locals to stay informed about daily UV exposure risks, ensuring enjoyable outdoor activities while prioritizing skin safety.
At sunrise, the UV Index begins its ascent, peaking at 1 by 07:00. As the day progresses, it rises steadily, hitting 2 by 08:00 and reaching a moderate 3 by 09:00. The intensity ramps up significantly from 10:00, where it soars to 6, and then it continues its climb to a striking 10 at 12:00. The highest point arrives at 13:00 and 14:00, where the UV Index maxes out at 11, signaling a time when sun protection is crucial. As the afternoon wanes, the index gradually decreases, settling at 9 by 15:00. By late afternoon, the values dip to 4 at 17:00, and then cool down to 2 by 18:00, before fading to 1 by 19:00 as daylight fades. It's a clear reminder to stay protected during the sunniest hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 11 | 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, the UV Index exhibits significant seasonal variations, peaking during the summer months of May to August, where it reaches extremes of 11 to 12. The highest risk occurs in May, June, and July, with burn times as short as 10 minutes under these conditions. March and April also present considerable UV exposure, categorized as very high, with burn times of just 15 minutes. Visitors and residents should exercise caution from late winter through summer, especially during these high-risk months, by seeking shade, wearing protective clothing, and applying broad-spectrum sunscreen regularly to minimize the risk of skin damage. As the season transitions into fall and winter, UV levels decrease, offering more moderate exposure from October to December.
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 |
| Mountain View | 4 | 6 | 8 | 10 | 11 | 12 | 12 | 11 | 10 | 7 | 5 | 3 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |