Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Shimodate, Japan, where the risk of harmful UV radiation is significant, particularly during peak hours. With a climate classified as Cfa, Shimodate experiences warm summers that heighten exposure to UV rays, especially between 10 AM and 2 PM, when the index reaches its highest points of 10. Being aware of UV levels not only helps in preventing painful sunburns but also plays a vital role in long-term skin health. Knowing when to seek shade or apply sunscreen can make all the difference in enjoying the beautiful outdoors while protecting your skin.
In the morning, the UV Index starts off relatively low, peaking at 3 by 7 AM. As the day progresses, it steadily climbs, reaching a notable high of 10 at both 11 AM and 12 PM—this is the time to be cautious! The index then begins to dip and falls back to a moderate level of 4 by 3 PM, before dwindling to 1 by 5 PM, and finally settling at 0 by 7 PM. For those enjoying outdoor activities, it’s essential to stay sun-smart during the mid-day hours when UV radiation is at its peak!
| 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 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The seasonal changes in UV Index reveal significant variations throughout the year, with the highest levels occurring in the summer months. March marks the transition into the high-risk category with a UV Index of 7, and by April and May, it escalates to 9 and 10 respectively, indicating very high levels of UV radiation. July reaches its peak at an extreme level of 11, posing the highest risk for skin damage with a burn time of only 10 minutes. Post-summer in August and September, UV levels remain notably high, while October drops to a high level of 6, still warranting caution. January, February, November, and December exhibit moderate UV levels, with burn times allowing for more extended exposure without burns. For both visitors and residents, it is vital to take protective measures during the high-risk months of March to September, including wearing sunscreen, protective clothing, and seeking shade during peak hours to minimize UV exposure.
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 |
| Shimodate | 3 | 5 | 7 | 9 | 10 | 10 | 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 |