Last updated: June 2, 2025
Understanding the UV Index is crucial for the residents and visitors of Chang'an, China, where sun exposure can vary significantly throughout the day. Knowing the UV levels not only helps in preventing sunburn and protecting skin health, but also empowers you to make informed decisions about outdoor activities. Given Chang'an's Cfa climate, characterized by hot summers and ample sunlight, awareness of peak UV exposure times is vital—especially when the index can soar to a maximum of 11 around midday. Stay informed to enjoy the sun safely!
The UV Index throughout the day showcases a remarkable rise, peaking impressively at 11 between noon and 1 PM. Starting with a modest 1 at 7 AM, the index escalates to around 3 by 8 AM and rapidly climbs, hitting 5 by 9 AM. The ascent continues as the sun reaches its zenith, soaring to 8 at 10 AM and breaching the 10 mark by 11 AM. As we reach peak sun hours, it stabilizes at 11 for both 12 PM and 1 PM, before gradually descending to 9 at 2 PM and tapering off to 7 by 3 PM. The latter part of the afternoon sees a gentle decline to 4 at 4 PM, finally returning to the morning's low of 1 by 6 PM, and maintaining this relaxed level through 7 PM. It's a vivid reminder of the sun's strength, urging outdoor enthusiasts to stay sun-smart during the intense midday hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index shows significant seasonal variation, with the highest risk months occurring from June to August. During this peak summer period, the UV Index reaches 12, categorized as extreme, with a burn time of just 10 minutes. As a result, it is crucial for visitors and residents to take precautions such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours. The preceding months of March, April, and May also present very high levels of UV exposure, especially in April and May when the Index reaches 10. Conversely, the UV levels drop considerably in the winter months, with December showing a moderate Index of 4 and a burn time of 30 minutes. Overall, vigilance during the high UV season is essential to prevent skin damage, while winter offers a more forgiving sun exposure environment.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Beijing UVI | 2 | 3 | 5 | 8 | 9 | 9 | 10 | 9 | 7 | 6 | 4 | 2 |
| Chengdu UVI | 5 | 6 | 8 | 10 | 12 | 11 | 11 | 10 | 11 | 8 | 6 | 4 |
| Shanghai UVI | 5 | 6 | 8 | 10 | 10 | 11 | 12 | 11 | 11 | 8 | 6 | 4 |
| Chang'an | 6 | 7 | 8 | 10 | 10 | 11 | 12 | 12 | 10 | 8 | 7 | 4 |
| Guangzhou UVI | 7 | 9 | 11 | 12 | 13 | 13 | 13 | 12 | 11 | 10 | 9 | 7 |
| Shenzhen UVI | 7 | 10 | 12 | 12 | 14 | 13 | 13 | 13 | 12 | 11 | 9 | 7 |