Last updated: May 3, 2025
Understanding the UV Index in Tsushima, Japan is crucial for protecting your skin and maintaining overall health under the sun. With varying UV levels throughout the day, awareness helps in preventing painful sunburns and reducing the long-term risks of skin damage. Tsushima's humid subtropical climate typically brings bright sunny days, especially during peak hours when the UV Index can soar to 10, indicating a very high risk of harm from unprotected sun exposure. Stay informed and take necessary precautions to enjoy the beauty of Tsushima while keeping your skin safe!
As the sun rises, the UV Index gradually transitions from a mild 1 at 07:00 to an invigorating 3 by 08:00. The peak UV intensity hits its stride between 12:00 and 13:00, reaching a striking 10, a clear call for sun protection. As the afternoon progresses, the index begins to decline, tapering off to 8 at 14:00, 6 at 15:00, and eventually settling to a gentle 2 by 17:00. By evening, the UV levels dip back down, returning to a safe 1, indicating it's time to relax and enjoy the cooler, softer light of sunset.
| 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 | 7 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 6 | 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 exhibits significant seasonal changes, with high-risk months primarily occurring from March to September. During these months, UV levels climb sharply, peaking at an extreme 12 in July and August, where the burn time is reduced to just 10 minutes. As summer transitions to fall, UV exposure slightly declines but remains notable, hitting 10 in April, May, and September, with burn times of only 15 minutes. Visitors and residents are strongly advised to take precautions during these high-risk months by wearing sunscreen, protective clothing, and sunglasses, particularly during midday when the sun's rays are most intense. From late fall through winter, while the UV Index drops to moderate levels (3-5), it's still important to remain cautious, especially if spending extended time outdoors.
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 |
| Tsushima | 4 | 5 | 7 | 10 | 10 | 11 | 12 | 12 | 10 | 7 | 5 | 3 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |