Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Harper, United States, where the climate often presents a mix of sunny days and seasonal variations. The UV Index provides essential information about the strength of ultraviolet radiation from the sun, helping you make informed decisions to protect your skin from harmful effects such as sunburn and long-term skin damage. With typical UV levels soaring to a maximum of 12 during midday, awareness is paramount to ensure skin health while enjoying the outdoor beauty of Harper. Don't let the sun's intensity catch you off guard—stay informed and safe!
As the sun rises, the UV Index starts at a mild 1 at 7:00 AM and remains low until 9:00 AM, where it climbs to 3. By 10:00 AM, the index accelerates to a moderate 5, but it’s at 11:00 AM that the heat intensifies, reaching 8. The peak occurs at 12:00 PM with a staggering value of 10, followed by the highest point of the day at 1:00 PM and 2:00 PM, where it maxes out at 12. After this peak, the index gradually declines: it drops to 10 by 3:00 PM and continues to decrease to 7 at 4:00 PM. By the late afternoon, the intensity wanes, falling to 5 at 5:00 PM and back down to 2 by 6:00 PM, before settling at 1 again as day turns to dusk by 7:00 PM. Remember to shield yourself during the midday hours when the UV radiation is at its most intense!
| 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 | 12 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index exhibits significant seasonal variation, with the highest levels typically occurring from April to September. During these months, the UV Index reaches extremes of 11 to 12, categorizing them as extreme exposure. February through October are considered high-risk months, especially April to August, where the burn time is as short as 10 minutes. It is vital for residents and visitors to take precautions, such as wearing sunscreen, protective clothing, and seeking shade during peak sunlight hours to minimize the risk of skin damage. As the UV Index decreases in the fall and winter months, November and December present lower risk, with more moderate values of 6 and 5, allowing for longer exposure times before burning occurs. Adjusting outdoor activities according to the UV index is essential for ensuring safety and health throughout the year.
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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |
| Harper | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 12 | 11 | 9 | 6 | 5 |