Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Sioux City, United States, as it provides timely information about the sun's intensity and potential risks to skin health. With UV levels peaking at 11 around midday during the warmer months, awareness is vital for effective sunburn prevention and long-term skin protection. Given Sioux City's Dfa climate, characterized by hot summers and mild winters, individuals must be vigilant about their sun exposure, especially during peak hours. By staying informed about the UV Index, residents can take proactive steps to safeguard their skin against harmful UV radiation.
As the day unfolds, the UV Index rises sharply, revealing the sun's intensity. At 7:00 AM, it starts low at 1, signaling a gentle morning. But by 10:00 AM, it surges to 5, urging early outdoor enthusiasts to apply sunscreen. The peak arrives at 1:00 PM with a blistering 11, indicating a strong need for protection. Following this zenith, the index gradually decreases, settling at 4 by 5:00 PM and then retreating to 1 as the sun sets at 7:00 PM. Throughout the day, it's clear: midday is when the sun is both brilliant and fierce, demanding our careful attention.
| 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 | 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 | 10 | very high | 15 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences significant seasonal changes, with high-risk months typically from April to September when the levels elevate to very high and extreme categories. Notably, June peaks at a UV Index of 11, indicating an extreme risk of harm from unprotected sun exposure, with a burn time of just 10 minutes. May and July follow closely behind, both maintaining UV indexes of 9 and 10. Visitors and residents are strongly advised to take precautions during these months, including seeking shade, wearing protective clothing, and applying sunscreen regularly to mitigate UV exposure. In contrast, from October to March, the UV Index drops to moderate or low levels, with burn times increasing to 30 to 45 minutes, making sun protection less critical during this period.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sioux City | 3 | 5 | 5 | 8 | 9 | 11 | 10 | 9 | 8 | 5 | 3 | 2 |
| 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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |