Last updated: June 2, 2025
Understanding the UV Index in Ushiku, Japan is crucial for overall skin health and sunburn prevention. As the sun rises higher in the sky, UV levels can peak dramatically—reaching highs of 11 around midday—which underscores the need for awareness and preparedness. Given Ushiku's Cfa climate, marked by warm summers and potentially intense sun exposure, being informed about daily UV fluctuations can help residents and visitors protect their skin from harmful rays. By staying aware of the UV Index, you can enjoy the sunny days ahead while minimizing the risk of skin damage and maintaining optimal skin health.
Throughout the day, the UV Index experiences a dynamic shift, peaking at 11 around 11:00 AM, reaching its most critical level. Early risers can expect a moderate level of 3 at 07:00 AM, which quickly escalates to 5 by 08:00 AM and hits 7 by 09:00 AM. As the sun climbs higher, the intensity escalates, showcasing a significant jump to 9 at 10:00 AM before reaching its zenith. After noon, there is a gradual decline: the index dips to 10 at 12:00 PM, then falls back to 9 at 1:00 PM, and continues to decrease, landing at 5 by 3:00 PM. Later, the UV levels diminish to 1 by 5:00 PM, and finally drop to 0 by 7:00 PM. It’s essential for outdoor adventurers to stay protected during the peak hours!
| 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 | 11 | extreme | 10 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, the UV Index experiences significant seasonal changes, with January and December presenting the lowest levels (UV Index 3) and the summer months of June and July reaching peak levels (UV Index 11), categorized as extreme. April and May also have very high readings (UV Index 9-10), indicating a gradual increase in risk as spring progresses into summer. March, August, and September maintain a high risk for UV exposure (UV Index 7-9). Visitors and residents are advised to take precautions from March through October, especially during the extreme months of June and July, by seeking shade, wearing protective clothing, and applying sunscreen regularly, as burn times decrease significantly to as little as 10 minutes during peak UV periods.
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 |
| Ushiku | 3 | 5 | 7 | 9 | 10 | 11 | 11 | 10 | 9 | 7 | 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 |