Last updated: July 2, 2025
Understanding the UV Index is crucial in Otsuchi, Japan, where the climate can influence daily sun exposure significantly. With the Cfb climate characterizing the region, residents and visitors alike should be aware of the potential for high UV levels, especially during midday when the index peaks at a harmful 10. This knowledge is vital for preventing sunburn and safeguarding overall skin health. By staying informed about UV fluctuations throughout the day, you can enjoy the outdoors safely while protecting yourself from the risks associated with prolonged sun exposure.
In the morning, the UV Index starts off relatively low, peaking at 3 by 7 AM. As the day progresses, it steadily climbs, reaching a notable high of 10 at both 11 AM and 12 PM—this is the time to be cautious! The index then begins to dip and falls back to a moderate level of 4 by 3 PM, before dwindling to 1 by 5 PM, and finally settling at 0 by 7 PM. For those enjoying outdoor activities, it’s essential to stay sun-smart during the mid-day hours when UV radiation is at its peak!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 5 | 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 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
As the seasons change, so do the UV Index levels, indicating varying levels of sun exposure risk throughout the year. From January to February, the UV Index remains moderate (3 to 4), with a burn time of 30 minutes. However, March marks the beginning of high-risk months, as the index rises to 6 (high) with a reduced burn time of 25 minutes. April sees a significant jump to 8 (very high), while May peaks at 9, both months requiring protective measures within 15 minutes of sun exposure. The summer months of June and July are especially concerning, with June reaching an extreme UV Index of 11 and July at 10, where a brief 10 to 15 minutes can lead to burns. Throughout August and September, the index remains high (10 and 9 respectively), before declining in October to a more manageable 6 (high) and returning to moderate levels in November and December. Visitors and residents alike should exercise caution, especially during the late spring and summer months, by wearing protective clothing, using sunscreen, and seeking shade to minimize UV 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 |
| Otsuchi | 3 | 4 | 6 | 8 | 9 | 11 | 10 | 10 | 9 | 6 | 4 | 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 |