Last updated: June 2, 2025
Understanding the UV Index is vital for residents of Ulsan, South Korea, where the climate’s Cfa classification brings warm summers and varying UV exposure throughout the day. With a peak UV Index reaching 11 during midday, awareness of UV levels is crucial not just for avoiding painful sunburns, but also for protecting long-term skin health. As the sun can be particularly intense, especially between 10 AM and 2 PM, knowing when to seek shade or apply sunscreen is essential for safeguarding your skin while enjoying the beautiful outdoor activities that Ulsan has to offer. Stay informed and stay protected!
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 |
The seasonal changes in UV Index reveal a significant fluctuation throughout the year, with high-risk months occurring from April to August, when the UV Index reaches very high to extreme levels. April and May showcase a peak UV Index of 10, while June and July escalate to an extreme 12, necessitating heightened caution. Residents and visitors are advised to take protective measures, such as wearing sunscreen, hats, and sunglasses, especially during these peak months when burn times drastically reduce to 10-15 minutes. As the season transitions into September and October, the UV levels remain high but start to lower, giving some reprieve, with burn times extending back to 25-30 minutes in the cooler months of November and December. Staying informed and vigilant during the warmer months can help prevent overexposure and skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Incheon UVI | 3 | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 9 | 6 | 4 | 3 |
| Seoul UVI | 3 | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 9 | 6 | 4 | 3 |
| Daejeon UVI | 3 | 5 | 7 | 9 | 9 | 11 | 11 | 12 | 10 | 7 | 5 | 3 |
| Daegu UVI | 3 | 5 | 7 | 10 | 10 | 11 | 12 | 12 | 10 | 7 | 5 | 3 |
| Ulsan | 3 | 5 | 7 | 10 | 10 | 11 | 12 | 12 | 10 | 7 | 5 | 3 |
| Busan UVI | 4 | 5 | 7 | 10 | 10 | 11 | 12 | 12 | 10 | 7 | 5 | 3 |