Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Minamikyushu, Japan, where the combination of a humid subtropical climate and high summer temperatures can lead to significant sun exposure. With peak UV levels reaching as high as 12 during midday hours, awareness of daily UV fluctuations can help protect against sunburn and long-term skin health issues. Recognizing these levels fosters responsible sun-safe behaviors, ensuring that everyone can enjoy the beautiful outdoors while minimizing risks associated with overexposure to harmful ultraviolet rays. So, before heading out, take a moment to check the UV Index and equip yourself with the knowledge to stay safe under the Japanese sun!
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 exhibit significant seasonal changes, with higher UV exposure occurring in the spring and summer months. From March to September, the UV Index reaches extreme levels, particularly peaking in August at 13, resulting in a burn time as short as 10 minutes. The months of April to August are particularly high-risk for sunburns and skin damage, requiring vigilant sun protection measures. Conversely, during the cooler months of January and December, the UV Index drops to a moderate level of 5, offering a safer environment for outdoor activities. Visitors and residents are strongly advised to use sunscreen, wear protective clothing, and seek shade during peak hours, especially from March through September, to minimize UV exposure and protect their skin health.
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 |
| Minamikyushu | 5 | 6 | 10 | 11 | 12 | 12 | 12 | 13 | 11 | 8 | 6 | 5 |