Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Osaki, Japan, where the sun can be surprisingly intense. Knowing the UV levels helps in taking necessary precautions to prevent sunburn and protect your skin health. With a Cfa climate characterized by hot summers, the UV exposure typically peaks between 11:00 AM and 1:00 PM, reaching alarming levels of up to 13. Staying informed about the UV Index not only aids in enjoying the outdoors safely but also fosters long-term skin health in this vibrant city.
The UV Index for the day exhibits a striking daytime peak, rising steadily from a gentle 1 at 07:00 to an intense 13 by 12:00. As the sun reaches its zenith, the 11:00 and 12:00 hours warn of heightened exposure, with the index hitting its maximum at 13:00 before beginning its gradual decline. By 15:00, it slips to 7, reminding us that even in the afternoon, protection is vital. As the day winds down, the UV levels fall back to a safe 1 by 18:00, ensuring a return to safer conditions for evening activities. Stay vigilant and protect your skin during those midday hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 7 | 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 fluctuates significantly, indicating varying levels of sun exposure risk. From January to February, the index increases from 5 (moderate risk) to 6 (high risk), suggesting a gradual need for sun protection. As spring approaches in March and April, the index peaks at 10 (very high risk), requiring increased caution. The summer months of May, June, July, and August reach their highest levels at 12 and 13 (extreme), with only 10 minutes of sun exposure before burning occurs. Although the UV index slightly decreases in September (11) and October (8), it remains high, continuing to warrant protective measures. The year concludes with a return to moderate levels in November (6) and December (5). Visitors and residents are advised to prioritize sun safety during the high-risk months from March through October, utilizing sunscreen, wearing protective clothing, and seeking shade during peak sunlight hours to minimize the risk of sunburn and long-term skin 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 |
| 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 |
| Osaki | 5 | 6 | 10 | 10 | 12 | 12 | 12 | 13 | 11 | 8 | 6 | 5 |