Last updated: July 2, 2025
Understanding the UV Index is essential for residents of Johnston City, United States. The importance of monitoring these levels cannot be overstated, as they play a critical role in preventing sunburn and maintaining skin health. With a humid subtropical climate (Cfa), Johnston City experiences varying UV exposure throughout the day, peaking at a concerning 10 between noon and 2 PM. Being aware of these fluctuations helps you safeguard your skin, ensuring you enjoy the outdoors while minimizing the risks associated with overexposure to harmful UV rays.
The UV Index data unveils a dynamic progression of sun intensity throughout the day. Starting low at 1 at 07:00, the index gradually escalates, reaching maximum levels of 10 between 12:00 and 14:00. This peak signals a critical time for sun protection. As the afternoon wanes, the index tapers off to 8 at 15:00, and then descends further to 3 by 17:00, and 2 by 18:00. Ultimately, the day concludes softly with a return to 1 at 19:00. It's essential to stay vigilant during those peak hours to safeguard your skin while enjoying the sun!
| 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 | 8 | very high | 15 min |
| 12:00 | 10 | 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 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits significant seasonal variations that are crucial for both residents and visitors to consider. From January to February, the UV Index remains in the moderate category (3-5) with a burn time of 30 minutes, indicating relatively lower risk. However, as spring approaches, March brings an increase to a high index of 7, necessitating caution with a reduced burn time of 25 minutes. The most critical months for UV exposure occur from April to June, where the index peaks at 11, categorized as extreme and resulting in a burn time of just 10 minutes. July and August maintain similar high levels, followed by a slight decline in September (9). As the year winds down, the UV risk lessens, with October returning to high levels (7) and burn time increasing to 25 minutes, before settling back to moderate levels by year’s end in November and December. Visitors and residents are advised to take extra precautions during the high-risk months of April to September, including using sunscreen, wearing protective clothing, and seeking shade, especially during peak hours.
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 |
| Johnston City | 3 | 5 | 7 | 10 | 11 | 11 | 10 | 10 | 9 | 7 | 5 | 3 |
| 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 |