Last updated: May 3, 2025
Understanding the UV Index in Yatsushiro, Japan is crucial for residents and visitors alike, as it helps to safeguard against harmful sun exposure. With the peak UV levels reaching an alarming 12 between noon and 1 PM, being aware of the UV Index can significantly aid in sunburn prevention and protect skin health. In Yatsushiro's Cfa climate, characterized by warm summers and mild winters, awareness of UV exposure risks is essential, especially during the midday hours when the sun's rays can be strongest. Stay informed and enjoy Yatsushiro's beautiful outdoors safely!
The UV Index throughout the day showcases a dynamic shift in sun intensity, peaking at 12 around noon. Beginning with a gentle 2 at 7:00 AM, the index steadily increases, hitting 11 by 11:00 AM as the sun climbs higher. By 12:00 PM, the sun reaches its zenith at 12, marking the highest UV exposure, making sun safety a priority. As the afternoon progresses, from 1:00 PM to 3:00 PM, the UV Index gradually decreases to 9 by 2:00 PM and 7 by 3:00 PM. The day winds down with a notable drop in intensity, returning to a mild 1 by 6:00 PM, emphasizing that the safest time to enjoy the sun is before noon or after 4:00 PM.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | 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 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | 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, UV Index levels fluctuate, indicating varying sun exposure risks. High-risk months are predominantly from March to September, where the UV Index frequently reaches extreme levels (10-13), with May to August being critically important, showing consistent values of 12 or higher. In March, the UV Index rises sharply to 9, followed by April and May with values of 10 and 12 respectively. It's vital for residents and visitors to understand that during this period, burn times decrease significantly to just 10 minutes, necessitating proactive sun safety measures such as wearing sunscreen, protective clothing, and seeking shade, especially between 10 AM and 4 PM. As the year progresses into the fall, UV levels gradually decline, but caution is still advised in October when the index remains high at 8. In winter, UV exposure returns to moderate levels, allowing for longer burn times in January and December, yet awareness and prevention remain essential 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 |
| Yatsushiro | 5 | 6 | 9 | 10 | 12 | 12 | 13 | 13 | 11 | 8 | 6 | 4 |