Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Shonai, Japan, where the unique climate offers both beautiful sunny days and significant sun exposure risks. With UV levels reaching as high as 11 during midday hours, being mindful of these readings is essential for sunburn prevention and maintaining skin health. Shonai's temperate climate not only brings enjoyable warmth but also requires awareness of UV radiation's potential dangers. By staying informed about the UV Index, Shonai residents can enjoy the outdoors safely while protecting their skin from harmful effects of excess sun exposure.
As the day unfolds, the UV Index reaches its peak, offering a clear picture of solar intensity. Starting at a mild 3 by 07:00, it gradually climbs to a striking 11 by 12:00, marking the day’s hazardous sunny point. From there, it gently descends, hitting 10 at 13:00 before tapering off to a more manageable 5 by 15:00. By late afternoon, the index drops further to 1 by 17:00, indicating minimal UV exposure. As the evening approaches, the UV Index dwindles to 0 after 19:00, signaling a safe retreat from sun exposure. Overall, it's crucial to be sun-smart between 10:00 and 14:00, when the UV levels are at their highest!
| 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 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 10 | 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 |
Throughout the year, the UV Index demonstrates significant seasonal variation, impacting sun safety for residents and visitors. With moderate exposure levels in January and February (UV Index 3-4), individuals can safely enjoy outdoor activities with a burn time of 30 minutes. As we move into March, the UV Index reaches a high level of 6, reducing burn time to 25 minutes, and continues to escalate through April and May, where it peaks at very high levels of 9, necessitating a burn time of just 15 minutes. The extreme risk months of July and August, with a UV Index of 11, emphasize the need for heightened sun protection, allowing only 10 minutes of unprotected sun exposure. The UV Index decreases again in September to 9, remains at 6 in October, and returns to moderate levels in November and December. To ensure safety, visitors and residents should adopt protective measures—such as sunscreen and clothing—during the high-risk months of April through August, particularly on the most intense days when UV levels peak.
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 |
| Shonai | 3 | 4 | 6 | 9 | 9 | 10 | 11 | 11 | 9 | 6 | 4 | 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 |