Last updated: August 1, 2025
Understanding the UV Index is essential for residents of Ishiki, Japan, especially as the region's Cfa climate brings both warmth and risk when it comes to sun exposure. With peak UV levels reaching 12 around noon, awareness of these measurements is crucial for preventing sunburn and protecting skin health. Knowing the UV index allows you to plan outdoor activities safely, minimizing your risk of skin damage while enjoying the vibrant beauty of Ishiki's landscapes. Stay informed, stay safe, and make the most of your time under the sun!
The UV Index for the day reveals a dynamic trajectory of sun intensity, peaking at 12 around noon. From the early hours, starting at 2 at 7:00 AM, the index climbs steadily, reaching 7 by 9:00 AM. As the sun reaches its zenith, the UV levels soar, hitting their maximum of 11 at 11:00 AM and remaining incredibly high at 12 from 12:00 PM to 1:00 PM. However, as the afternoon progresses, the index begins to decline, tapering down to 8 at 2:00 PM and further decreasing to 6 by 3:00 PM. By the evening, the UV Index drops significantly, settling back to 2 at 5:00 PM and finally waning to a calming zero by 7:00 PM. It's a day to stay sun-smart, especially during those peak midday hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 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 |
Throughout the year, UV exposure varies significantly, with the highest risk typically occurring from March to September. During this period, the UV Index reaches its maximum, peaking at 12 in July, categorizing it as extreme, with a minimum burn time of just 10 minutes. April and May also present high-risk months, with UV Index values of 10 and 11, respectively. As a result, residents and visitors are advised to take precautions, including frequent application of sunscreen, wearing protective clothing, and seeking shade, particularly during midday hours when the sun's rays are strongest. In contrast, winter months see a decline in UV levels, with January to February falling into the moderate exposure category, while October provides a brief respite at a high level but still requires attention. Staying informed and proactive can help ensure safety from harmful UV radiation throughout the seasons.
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 |
| Ishiki | 4 | 5 | 8 | 10 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |