Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors of Riverside, United States, where the sun can shine brightly throughout the year. Being aware of UV levels helps you prevent sunburn and protect your long-term skin health, making it essential to check the index daily. Riverside's Cfa climate brings warm summers and mild winters, but this also means increased risks of UV exposure, especially during midday hours when the index peaks. Stay informed and enjoy the sunshine safely!
As the day unfolds, the UV Index ramps up rapidly, starting from a gentle 1 at 7:00 AM and gradually climbing to reach a peak of 11 by 1:00 PM and 2:00 PM. This hour marks the height of sun exposure, where the risk of harm from unprotected sun exposure is significant. After this peak, the index begins to descend, dropping to 9 by 3:00 PM, then tapering off to 6 at 4:00 PM, and finally settling back to a mild 1 by 7:00 PM. For those planning outdoor activities, early afternoon is best approached with caution and protection—a reminder that while the sun can be enjoyable, it demands respect!
| 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 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, so too does the UV Index, which significantly impacts exposure and burn time. From January's moderate UV Index of 5 with a burn time of 30 minutes, we enter a period of increasing risk; February through April sees a jump into the very high category, consistently reaching 8 to 10. The height of summer marks the peak danger, with May through July classified as extreme (UV Index 11 to 12), where just 10 minutes of exposure can lead to burns. August returns to an extreme level before tapering off in September and October to a very high index of 10 and 8 respectively. November and December bring a return to high and moderate levels, with more forgiving burn times of 25 and 30 minutes. Visitors and residents are advised to take necessary precautions, particularly during the high-risk months of February through October, wearing sunscreen, protective clothing, and seeking shade, especially during peak sunlight 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 |
| Riverside | 5 | 8 | 9 | 10 | 11 | 11 | 12 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |