Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Mountain View, United States, where the sun's rays can pack a powerful punch, especially during peak hours. Monitoring UV levels is essential not only for preventing painful sunburns but also for protecting long-term skin health. With a mild Cfa climate, Mountain View experiences significant solar exposure, particularly from 10 AM to 2 PM when UV Index readings can soar to level 12. By being aware of these levels, locals can make informed decisions about sun protection, ensuring a safe and enjoyable outdoor experience.
As the sun rises, the UV Index starts off low at 1 from 7:00 AM to 9:00 AM, making it a safe time for outdoor activities. However, as the clock ticks toward 10:00 AM, the index surges to 5, signaling that precautions should be taken. The peak intensity hits at 12:00 PM, with the UV Index soaring to a striking 10. This is where sun safety becomes crucial, especially as it reaches its highest point of 12 by 1:00 PM and remains there until 2:00 PM. After noon, the index gradually declines, dropping to 5 by 5:00 PM, and then falling back to a safe level of 1 by 7:00 PM. Be sure to stay protected during those midday hours for the best outdoor experience!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 8 | very high | 15 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, so do UV levels, with notable peaks during the summer months. From January (UV Index 4, moderate exposure) to February (UV Index 6, high), there is a gradual increase in UV radiation. However, March and April see a significant rise, with UV levels reaching 8 and 10 respectively, categorizing them as very high. May through August marks the highest risk, with an extreme UV Index of 11 to 12 and a minimum burn time of just 10 minutes. This period is crucial for visitors and residents to exercise heightened caution and protection measures such as sunscreen, protective clothing, and shade. As summer fades into September (UV Index 9, very high) and declines into the more moderate levels of October (UV Index 7) and November/December (UV Index 4), it is essential to remain vigilant, particularly during the peak months, to minimize the risk of UV exposure.
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 | 11 | 12 | 11 | 9 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |