Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Rapid City, as it plays a significant role in protecting skin health and preventing sunburn. With the city’s Dfa climate, characterized by distinct seasons and sunny summers, UV levels can soar, particularly during midday hours. For instance, rapid increases in UV Index—from a moderate level at 9 AM to a striking peak of 11 by 1 PM—underscore the need for vigilance. By being informed about daily UV levels, residents can take proactive measures to safeguard their skin and enjoy the outdoors safely.
The UV Index steadily climbs as the day progresses, starting from a mild 1 at 7:00 AM and reaching a peak of 11 by 1:00 PM. Sun-seekers and outdoor enthusiasts should be mindful, as the index hits a high of 10 at 12:00 PM, signaling significant UV exposure. After this peak, the index gradually decreases, dropping to 8 by 3:00 PM, and continuing to decline to 1 by 7:00 PM. For safe sun enjoyment, it’s best to take precautions during those high UV hours, particularly between 11:00 AM and 2:00 PM. Remember to sport your hats and sunscreen!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 9 | 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 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV levels exhibit significant seasonal changes, with the highest risk months occurring from April to August, when the UV Index reaches extremely high levels (9-11). Notably, June and July are the peak months, with an index of 11, indicating extreme exposure risks and a burn time as short as 10 minutes. As the year progresses, UV levels begin to decline in August and gradually drop to moderate levels by October, November, and December, where burn times increase significantly. Visitors and residents should take precautionary measures during high UV months by wearing protective clothing, applying sunscreen regularly, and minimizing sun exposure during peak hours, especially from late spring through summer.
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 |
| Rapid City | 3 | 5 | 6 | 9 | 9 | 11 | 11 | 10 | 8 | 5 | 3 | 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 |