Last updated: June 2, 2025
Awareness of the UV Index is crucial for residents and visitors in Matsumoto, Japan, where the combination of its Dfb climate and high altitudes can lead to significant sun exposure. Understanding UV levels not only helps in preventing sunburn but also plays a vital role in maintaining long-term skin health. During peak hours, particularly around noon when the UV Index can reach as high as 11, the risk of harmful UV radiation increases dramatically. Being informed about these risks can help you enjoy Matsumoto's beautiful landscapes while protecting your skin from potential damage.
The UV Index throughout the day exhibits a clear peak around midday, reflecting the sun's intensity. Starting from a mild 2 at 07:00, it swiftly rises to a moderate 5 by 08:00. By 09:00, the index escalates to a more intense 7, reaching a notable 10 at 10:00, and hitting its maximum of 11 at both 11:00 and 12:00. As the afternoon progresses, the index begins to decline, dropping to 10 at 13:00, then gradually lowering to 8 at 14:00 and 6 by 15:00. The evening sees a rapid decrease, with values falling to 3 at 16:00, then to 2 at 17:00, and finally tapering off to 1 at 18:00 and 0 by 19:00. This pattern emphasizes the importance of sun protection during the peak hours of 11:00 to 14:00 when UV exposure is highest.
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 2 | low | 45 min |
08:00 | 5 | moderate | 30 min |
09:00 | 7 | high | 25 min |
10:00 | 10 | 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 | 6 | high | 25 min |
16:00 | 3 | moderate | 30 min |
17:00 | 2 | low | 45 min |
18:00 | 1 | low | 45 min |
19:00 | 0 | low | 45 min |
Throughout the year, the UV Index exhibits significant seasonal changes, peaking during the summer months. The highest risk for UV exposure occurs from March through August, with May to August categorized as extreme with UV Index values reaching up to 12. This means that residents and visitors should be particularly vigilant during these months, as the burn time reduces to just 10 minutes under direct sunlight. From September to February, the UV Index decreases, with January and December considered moderate, allowing for longer exposure times of 30 minutes. It is essential to take precautions such as wearing sunscreen, protective clothing, and seeking shade, especially during the high-risk months to minimize the risk of skin damage.
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 |
Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |
Matsumoto | 4 | 6 | 9 | 10 | 11 | 11 | 11 | 12 | 10 | 7 | 5 | 4 |