Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Harrisburg, Pennsylvania, where the sun shines brightly during warmer months. High UV levels can lead to serious skin health issues, including painful sunburns and increased risks of skin cancer, making it essential to monitor UV intensity throughout the day. With a humid continental climate (Dfa), Harrisburg experiences significant variations in UV exposure, peaking in the early afternoon. From a moderate UV Index of 1 in the morning to a potent 10 during midday, being informed can empower you to take necessary precautions and enjoy the sun safely.
From the early morning hours, UV Index levels remain low, peaking at 1 until 09:00. As the day unfolds, there's a notable rise, hitting 5 by 10:00 and soaring to a striking 10 at its zenith between 13:00 and 14:00. This period marks the sun's intensity at its strongest, urging caution for those venturing outdoors. After 14:00, the index gradually declines, settling to 3 by 18:00. As dusk approaches, the UV Index drops further to 1 by 19:00, indicating a safe return for outdoor activities. Stay protected during the midday hours when the sun’s rays are at their peak!
| 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 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV levels exhibit significant seasonal changes, with the most intense exposure occurring during the summer months. January and December have the lowest UV Index values (2), indicating low risk for sunburn, while February and March present a moderate risk with an index of 5. High-risk months include April through September, where UV Index values peak at 11 in June, categorizing it as extreme exposure. During these peak months, residents and visitors are advised to practice sun safety by seeking shade, wearing protective clothing, and applying sunscreen frequently, especially between 10 AM and 4 PM when UV rays are strongest. As the UV levels decrease in October and November, precautions can be relaxed, but maintaining a moderate level of awareness remains essential.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Harrisburg | 2 | 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 |