Last updated: May 3, 2025
As residents and visitors of Katori-shi, Japan, enjoy the beauty of the region, it’s crucial to stay informed about the UV Index to ensure optimal skin health and sunburn prevention. Understanding the UV levels throughout the day helps you take proactive measures against potential skin damage, especially as Katori-shi, with its Cfa climate, experiences varying UV exposure risks from morning to afternoon. With peak UV indices reaching up to 10 between 11:00 AM and 12:00 PM, being aware of these levels not only aids in safeguarding your skin but also enhances your overall outdoor experience in this vibrant city.
In the morning, the UV Index starts off relatively low, peaking at 3 by 7 AM. As the day progresses, it steadily climbs, reaching a notable high of 10 at both 11 AM and 12 PM—this is the time to be cautious! The index then begins to dip and falls back to a moderate level of 4 by 3 PM, before dwindling to 1 by 5 PM, and finally settling at 0 by 7 PM. For those enjoying outdoor activities, it’s essential to stay sun-smart during the mid-day hours when UV radiation is at its peak!
| 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 | 10 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | 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, 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 |
| Katori-shi | 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 |