Last updated: July 2, 2025
In Asahimachi, Japan, awareness of the UV Index is crucial for safeguarding skin health and preventing sunburns. Understanding UV levels is not just about avoiding discomfort; it's essential for long-term skin protection, especially in a region with a Dfb climate where sunlight can be both strong and persistent. During the summer months, UV exposure can peak significantly, as indicated by the high UV Index readings from 9 AM to 1 PM, reaching a maximum of 9. Being informed about these levels empowers residents and visitors to make mindful choices about sun protection, ensuring enjoyable outdoor experiences without the risk of harmful effects.
At 07:00, the UV Index begins at a modest 3, signaling a gentle start to the day. By 08:00, it climbs to 5, suggesting it's time to apply some sunscreen if you plan to be outdoors. As the sun reaches its peak around 10:00, the index hits a robust 8 and reaches its pinnacle at 11:00 and 12:00 with a peak of 9. This signifies a high risk of harm from unprotected sun exposure, making it crucial to seek shade or wear protective clothing during these hours. As the afternoon progresses, the index gradually decreases, dropping to 7 by 14:00, then to 4 at 15:00, and finally tapering off to 3 by 16:00. As the day winds down, the UV Index diminishes further, falling to 1 from 17:00 onward, indicating minimal risk for sun exposure. Stay safe and be sun smart!
| 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 | 8 | very high | 15 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences significant seasonal variations, with the highest levels occurring during the summer months. From May to September, the UV Index rises to very high levels (8-9), indicating a critical period for sun exposure and skin protection, with a burn time of only 15 minutes. The high-risk months for UV exposure are May, June, July, and August, where residents and visitors should take extra precautions against sunburn and skin damage. In contrast, the winter months of January and December feature a low UV Index of 2, allowing for longer safe exposure times of 45 minutes. To protect your skin, it is advisable to wear sunscreen, hats, and protective clothing, especially during the peak hours between 10 AM and 4 PM, particularly in the high-risk months.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Asahimachi | 2 | 3 | 6 | 7 | 8 | 9 | 9 | 9 | 8 | 5 | 3 | 2 |
| 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 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |