Last updated: June 2, 2025
In Ashburn, United States, staying aware of the UV Index is essential for protecting your skin from harmful solar radiation. Understanding UV levels not only aids in preventing painful sunburns but also plays a crucial role in long-term skin health. With Ashburn's Cfa climate, characterized by humid subtropical conditions, residents are at risk for significant UV exposure, especially during midday hours when the index can reach a peak of 11. By keeping an eye on the UV Index, you can enjoy the outdoors safely while safeguarding your skin from the sun’s damaging effects.
The UV Index for the day starts gently, with values peaking at 1 from 7:00 AM to 8:00 AM. As the sun rises higher, the index escalates, reaching 3 by 9:00 AM. A significant surge occurs between 10:00 AM and 2:00 PM, where it escalates dramatically, peaking at a striking 11 from 1:00 PM to 2:00 PM—a clear indication to seek shade and protect your skin. The afternoon sees a gradual decline, with figures dropping to 10 at 3:00 PM, then to 7 at 4:00 PM. As the day winds down, the UV Index returns to safer levels, resting at 1 by 7:00 PM. Keep in mind, high UV levels call for precautions, especially in the midday sun!
| 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 | 10 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index levels fluctuate significantly, with the highest risk observed during the spring and summer months. From February to August, the UV Index remains at a very high to extreme level, peaking at 11 in May, June, July, and August, where the burn time is as short as 10 minutes. Visitors and residents are advised to take extra precautions during these months by wearing protective clothing, applying sunscreen regularly, and seeking shade, especially during midday hours. In contrast, January and December experience moderate UV levels, allowing for longer exposure times of 30 minutes before burning. As the UV levels decline entering the fall months, particularly in November with a high index of 6 (burn time of 25 minutes), it is still prudent to remain vigilant against UV exposure.
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 |
| Ashburn | 5 | 8 | 9 | 10 | 11 | 11 | 11 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |