Last updated: May 3, 2025
In Hakodate, Japan, being aware of the UV Index is crucial for protecting your skin and overall health. Understanding UV levels helps you prevent painful sunburn and reduce long-term skin damage, especially during the peak hours when exposure is highest. With a Dfb climate, Hakodate experiences varying UV intensities throughout the year, but summer months can see higher levels, reaching a UV Index of 9 between 11:00 AM and 1:00 PM. Stay informed and take precautions to enjoy the beautiful sunny days while keeping your skin safe!
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 |
Throughout the year, UV index levels fluctuate significantly, indicating varying risks for sun exposure. January and December see low UV levels (Index 2), with extended burn times of 45 minutes, making sun safety less of a concern. In contrast, April to August marks a critical period with very high to extreme UV levels (Indexes 8 to 11) that dramatically decrease safe burn times to 15 minutes in April to July and just 10 minutes in August. May and June particularly stand out as high-risk months. As summer transitions into early fall, UV levels moderately decline but remain a risk with levels still at 8 in September, requiring continued vigilance. For optimal sun safety, visitors and residents are advised to monitor the UV index, especially during the high-risk months of April to August, adopting protective measures such as sunscreen, clothing, and shade to mitigate 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 |
| Hakodate | 2 | 3 | 5 | 8 | 9 | 10 | 10 | 11 | 8 | 6 | 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 |