Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Rio Vista, United States, where sunny days are plentiful and UV exposure can be significant. Knowing the daily levels of ultraviolet radiation helps in making informed decisions to protect against sunburn and long-term skin health issues. With a humid subtropical climate (Cfa), Rio Vista experiences varying UV levels throughout the day, peaking at dangerous levels between 11 AM and 2 PM. By staying aware of these fluctuations, you can enjoy the sun safely while safeguarding your skin.
The UV Index for the day showcases a striking pattern, starting moderate at 7:00 AM with a value of 1. As the sun climbs higher, the index steadily rises, hitting 3 by 9:00 AM, and then surging to a peak of 11 between 1:00 PM and 2:00 PM. This indicates a high risk of harm from unprotected sun exposure during midday. Following the peak, the UV Index gradually declines to 4 by 5:00 PM and further decreases to 1 by 7:00 PM, emphasizing the critical importance of sun protection during the intense midday hours. It’s advisable to seek shade and wear sunscreen if you're outside during the peak period!
| 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 | 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 shows significant seasonal changes, particularly peaking during the summer months. From January to February, the UV Index rises from a moderate level of 4 to a high 7, indicating the need for increased sun protection. The months of March through August are notably high-risk, as the UV Index remains in the very high to extreme category, reaching a peak of 11 in May through August, with a burn time of only 10 minutes; therefore, individuals should practice stringent sun safety, including wearing protective clothing and using sunscreen frequently. As we move into September and October, the UV Index decreases but remains a concern, especially in September with a UV of 10. By November and December, the levels drop back to moderate (4) and high (6), allowing for a temporary respite. Visitors and residents should remain vigilant during the high-risk months and adopt protective measures against harmful UV exposure, particularly from March through October.
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 |
| Rio Vista | 4 | 7 | 8 | 10 | 11 | 11 | 11 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |