Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Tsubata, Japan, where the climate features humid summers and mild winters that can heighten UV exposure risks. With peak UV levels reaching a striking 11 around noon, awareness becomes imperative to prevent sunburn and maintain long-term skin health. By monitoring daily UV readings, locals can take proactive measures to protect themselves against harmful rays—ensuring their time outdoors remains enjoyable and safe. Whether you're hiking, enjoying a sunny day at the park, or simply commuting, knowing the UV Index helps you make informed choices to safeguard your skin.
The UV Index peaks dramatically as the day unfolds, beginning at a mild 2 by 7:00 AM. As the sun climbs higher, the intensity builds steadily, reaching 4 by 8:00 AM and then soaring to 7 at 9:00 AM. The sun’s rays hit their zenith at 12:00 PM, with an intensity of 11, signaling the necessity for sun protection. With a slight dip, the index remains high at 10 by 1:00 PM, before gradually declining to 8 at 2:00 PM. The afternoon sees a gentle descent, with the index falling to 5 by 3:00 PM, then further to 3 at 4:00 PM. As evening approaches, the UV Index drops significantly, settling at a low of 1 by 6:00 PM and staying consistent through 7:00 PM. It’s a strong reminder to safeguard yourself during the midday hours when the sun is most potent!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 9 | 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 | 5 | moderate | 30 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 seasons change, so do UV levels, with significant increases during the warmer months. From March to August, the UV Index rises dramatically, peaking at 11 (extreme) in June, July, and August, where burn times are as short as 10 minutes. April and May also present high risk, with a UV Index of 10 (very high) and burn times of 15 minutes. Conversely, the risk decreases significantly in the cooler months, with a moderate exposure category during January, February, November, and December, allowing for 30 minutes of safe sun exposure. Visitors and residents should take extra precautions from March to September, using sunscreen, wearing protective clothing, and seeking shade, especially during peak hours, to minimize sun damage.
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 |
| Tsubata | 3 | 5 | 7 | 10 | 10 | 11 | 11 | 11 | 9 | 6 | 5 | 3 |
| 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 |