Last updated: June 2, 2025
Understanding the UV Index in Hitachi, Japan is crucial for protecting yourself from harmful ultraviolet radiation, especially given the region's humid subtropical climate. With high UV levels peaking at 11 around noon, knowing when to seek shade or apply sunscreen can significantly reduce the risk of sunburn and long-term skin damage. As you enjoy Hitachi's sunny days, being aware of the UV Index helps ensure that you maintain healthy skin while enjoying outdoor activities. Keep an eye on these levels to make the most of your time under the sun while prioritizing your 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 |
| Hitachi | 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 |