Last updated: June 2, 2025
Understanding the UV Index in Tatsuno, Japan, is critical for safeguarding your skin and overall health. With the region's Dfb climate, residents and visitors alike are frequently exposed to varying levels of UV radiation, particularly during the midday hours when the index peaks at 11, indicating a high risk for sunburn. By being aware of the UV index and taking proactive measures, you can prevent skin damage and enjoy the beautiful sunny days that Tatsuno has to offer while keeping your skin safe and healthy. Stay informed and make every sunny outing a safe one!
The UV Index throughout the day exhibits a clear peak around midday, reflecting the sun's intensity. Starting from a mild 2 at 07:00, it swiftly rises to a moderate 5 by 08:00. By 09:00, the index escalates to a more intense 7, reaching a notable 10 at 10:00, and hitting its maximum of 11 at both 11:00 and 12:00. As the afternoon progresses, the index begins to decline, dropping to 10 at 13:00, then gradually lowering to 8 at 14:00 and 6 by 15:00. The evening sees a rapid decrease, with values falling to 3 at 16:00, then to 2 at 17:00, and finally tapering off to 1 at 18:00 and 0 by 19:00. This pattern emphasizes the importance of sun protection during the peak hours of 11:00 to 14:00 when UV exposure is highest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 10 | very high | 15 min |
| 11:00 | 11 | extreme | 10 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 | 0 | low | 45 min |
Throughout the year, UV index levels fluctuate, with the most significant increases occurring from March to September. During these months, particularly in May, June, July, and August, the UV index reaches its peak at 12, categorized as extreme, with a burn time of just 10 minutes. March and April also present high risks, featuring very high UV levels of 9 and 10 respectively. Visitors and residents should be particularly vigilant in these high-risk months, applying sunscreen, wearing protective clothing, and seeking shade whenever possible. As UV levels decrease from late summer into fall and winter, with January and December categorized as having moderate exposure (UV index 4), precautions remain advisable to ensure skin protection year-round.
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 |
| Tatsuno | 4 | 6 | 9 | 10 | 11 | 11 | 12 | 12 | 10 | 7 | 5 | 4 |