Last updated: May 3, 2025
In Hirakawa, Japan, being aware of the UV Index is crucial for protecting your skin and overall health. With peak UV levels reaching 9 during midday, understanding these fluctuations can be vital in preventing sunburn and long-term skin damage. The climate here, characterized by warm summers and mild winters, means that residents and visitors alike must stay vigilant against harmful UV rays, especially during those sunny afternoon hours. By keeping an eye on the UV Index, you can enjoy Hirakawa’s beautiful outdoors while safeguarding your skin’s health.
As the sun rises, the UV Index begins its ascent, peaking at 11:00 AM and 12:00 PM with a blistering 9. The day starts gently, with 07:00 AM registering a modest 2, but by 09:00 AM, it climbs to a moderate 6. The intensity escalates, hitting 8 at 10:00 AM and reaching its zenith shortly after noon. After this peak, the index gradually dips, easing down to 6 by 2:00 PM, before falling further to 4 at 3:00 PM. As evening approaches, the UV radiation wanes significantly, dropping to 2 by 4:00 PM and near zero after sunset, signaling a shift in the skies. Remember to protect your skin during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | 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 | 6 | 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 |
As the seasons change, so do the UV index levels and associated risks for skin damage. During the winter months of January to February, the UV index remains moderate (3-4), allowing for a 30-minute burn time. However, starting in March, the UV index escalates to high (6), indicating the need for increased sun protection. The high-risk months peak from April to August, with the UV index reaching very high (8-10) and even extreme levels (11) in August, where burn times drop to just 10 minutes. September sees a decline to very high (9), while October returns to high levels (6) with a longer burn time of 25 minutes. As winter returns in November and December, the sun's strength diminishes, with indexes dropping to moderate and low (4 and 2), leading to safer burn times of 30 and 45 minutes, respectively. It is crucial for visitors and residents to use sun protection consistently during high-risk months and limit direct sun exposure, especially during midday hours.
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 |
| Hirakawa | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 11 | 9 | 6 | 4 | 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 |