Last updated: May 3, 2025
In Yamaguchi, Japan, staying informed about the UV Index is crucial for safeguarding your skin against harmful sun exposure. Understanding UV levels not only helps in preventing painful sunburns but also plays a vital role in maintaining long-term skin health. With Yamaguchi's climate characterized by its warm summers and moderate humidity, UV exposure can escalate, especially during peak hours when the index reaches its highest levels around noon. Being vigilant about the UV Index can empower you to enjoy outdoor activities while effectively protecting your skin from potential damage.
The UV Index paints a vivid picture of the sun's intensity throughout the day. Starting with a gentle 2 at 7:00 AM, the index climbs steadily, reaching 3 by 8:00 AM. As the sun rises higher, it peaks at an impressive 11 at noon, signaling a time when sun protection is crucial. The index begins to taper off in the afternoon, with readings of 10 at 1:00 PM and 8 at 2:00 PM, before gradually decreasing to 6 at 3:00 PM. By late afternoon, the UV Index returns to a more moderate 3 at 4:00 PM, and continues to decline, settling at 1 by 6:00 PM. It’s clear that the midday sun demands respect, making awareness of UV levels essential for outdoor safety.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the year progresses, the UV Index reveals significant seasonal changes and highlights high-risk months for sun exposure. From January to February, the UV Index remains in the moderate range (4-5), with a burn time of 30 minutes. However, starting in March, the UV Index surges to 8, classified as very high, drastically reducing safe exposure time to just 15 minutes. The peak risk occurs between April and August, with the UV Index reaching up to 12 (extreme), necessitating protective measures after just 10 minutes of sun exposure. As summer transitions to fall, the UV Index begins to decline, with September still presenting a very high level (10), before settling into high levels in October and November (6-7) with safer burn times of 25 minutes. December marks the lowest UV levels at 3, re-entering the moderate range. Visitors and residents are advised to exercise caution during the high-risk months of April to August, employing sunscreen, seeking shade, and wearing protective clothing to minimize the risks associated with intense UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sapporo UVI | 2 | 3 | 6 | 7 | 9 | 9 | 9 | 10 | 8 | 5 | 3 | 2 |
| Yokohama UVI | 3 | 5 | 8 | 9 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 4 |
| Tokyo UVI | 3 | 5 | 8 | 9 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 4 |
| Nagoya UVI | 4 | 6 | 8 | 10 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 3 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |
| Yamaguchi | 4 | 5 | 8 | 11 | 11 | 11 | 12 | 12 | 10 | 7 | 6 | 3 |