Last updated: July 2, 2025
Understanding the UV Index in Sano, Japan is crucial for maintaining skin health and preventing sunburn, especially given the area's Cfa climate that can expose residents and visitors to varying UV levels throughout the day. With peak UV readings reaching as high as 11 around midday, awareness of these levels is essential for outdoor activities and skin protection. By monitoring the UV Index, you can take proactive measures to shield yourself from the sun's harmful rays and enjoy the beautiful, sunny days in Sano more safely. Remember, even on cloudy days, UV rays can still cause damage, making it vital to stay informed about the current UV conditions.
The hourly UV Index reveals a dynamic rise and fall of sun intensity throughout the day. Starting at a mild 2 at 07:00, the index climbs steadily, reaching a peak of 11 at both 11:00 and 12:00, indicating a high risk of harm from unprotected sun exposure. As the afternoon sun begins to descend, the index tapers off to 9 at 13:00, then gradually decreases to 5 by 15:00. By 16:00, it drops to 3, signaling the end of peak sun strength, while cool evenings arrive with a return to 1 at both 17:00 and 18:00. Finally, at 19:00, the UV Index hits 0, marking a safe transition into the night. Stay protected during the day's brightest hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 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 |
| Sano | 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 |