Last updated: August 1, 2025
Understanding the UV Index in Ogasawara, Japan, is crucial for safeguarding your skin health and preventing sunburn. With UV levels peaking dramatically during the midday hours—reaching a maximum of 13 around noon—awareness of these figures empowers residents and visitors to take necessary precautions against the sun's harmful rays. Ogasawara's Cfa climate features warm temperatures and ample sunshine, resulting in elevated UV exposure risks throughout the year. By staying informed about UV levels, you can enjoy the beautiful outdoor scenery while protecting yourself from potential skin damage.
As the sun rises, the UV Index starts off at a moderate 3 at 07:00, making it a safe time for early risers. By 08:00, it climbs to 5, and shortly thereafter, at 09:00, it peaks at a striking 8. The sun reaches its zenith around 10:00, boasting a maximum intensity of 11, which calls for caution among sun-seekers. The intensity doesn't let up, maintaining a high of 13 by 11:00 and 12:00. As the afternoon progresses, the index begins to taper off, dropping to 11 at 13:00 and descending to 8 at 14:00. By 15:00, it dips further to 5, creating a more comfortable environment for outdoor activities. However, as the evening approaches, the UV levels drop significantly to 2 by 16:00, and then to a mere 1 by 17:00 and 18:00, before finally resting at 0 by 19:00. This data illustrates a clear pattern of rising and falling UV intensity, emphasizing the importance of protecting your skin during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 8 | very high | 15 min |
| 10:00 | 11 | extreme | 10 min |
| 11:00 | 12 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 5 | 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 |
Throughout the year, UV exposure varies significantly, peaking during the spring and summer months. Notably, March through September experience extreme UV levels, with indices consistently reaching 12 or higher, indicating a high risk for sunburn. In particular, April to July holds the highest UV ratings, making these months crucial for sun protection. High-risk months include February to October, with a sharp increase from February's very high index of 9 to April's extreme index of 13. Residents and visitors should be particularly vigilant in these months, limiting sun exposure between 10 AM and 4 PM and utilizing sunscreen, protective clothing, and sunglasses to mitigate UV damage effectively. As UV levels decrease in November and December, while still cautioning against exposure, the risk diminishes significantly.
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 |
| Ogasawara | 7 | 9 | 11 | 13 | 12 | 13 | 13 | 12 | 12 | 10 | 8 | 6 |