Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Ishioka, Japan, especially as the region experiences a humid subtropical climate (Cfa), which can lead to elevated UV levels. Knowledge of the daily UV levels is vital for preventing sunburn and maintaining skin health. With peak UV readings soaring to 11 around noon, awareness can help you take proactive steps to protect yourself during the most intense periods of sun exposure. Ishioka's climate brings unique risks, making it essential to monitor these levels for safe outdoor activities and overall well-being.
Throughout the day, the UV Index experiences a dynamic shift, peaking at 11 around 11:00 AM, reaching its most critical level. Early risers can expect a moderate level of 3 at 07:00 AM, which quickly escalates to 5 by 08:00 AM and hits 7 by 09:00 AM. As the sun climbs higher, the intensity escalates, showcasing a significant jump to 9 at 10:00 AM before reaching its zenith. After noon, there is a gradual decline: the index dips to 10 at 12:00 PM, then falls back to 9 at 1:00 PM, and continues to decrease, landing at 5 by 3:00 PM. Later, the UV levels diminish to 1 by 5:00 PM, and finally drop to 0 by 7:00 PM. It’s essential for outdoor adventurers to stay protected during the peak hours!
| 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 | 11 | extreme | 10 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index exhibits notable seasonal changes throughout the year, with high-risk months primarily occurring from March to September. March marks the shift to a high category (UV Index 7), while April and May escalate to very high (UV Index 9-10), culminating in extreme exposure levels during June and July (UV Index 11). As summer transitions to fall, the UV levels gradually decline, dipping to moderate levels by November and December. Visitors and residents should take necessary precautions, especially during the peak months of June and July, where the burn time is drastically reduced to just 10 minutes. It is advisable to wear protective clothing, apply sunscreen frequently, and seek shade during these high-risk times to minimize skin damage and health risks.
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 |
| Ishioka | 3 | 5 | 7 | 9 | 10 | 11 | 11 | 10 | 9 | 6 | 5 | 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 |