Last updated: June 2, 2025
In Seiro, Japan, understanding the UV Index is crucial for protecting your skin from harmful ultraviolet rays. With UV levels peaking at a high of 10 around midday, it’s essential to monitor these values to prevent sunburn and promote long-term skin health. Given Seiro's Cfa climate, characterized by warm summers and ample sunshine, residents and visitors alike should be aware of their UV exposure risks, particularly during the peak hours of 10 AM to 2 PM. By staying informed and taking appropriate sun safety measures, you can enjoy the beautiful outdoors while keeping your skin safe and healthy.
As the sun rises, the UV Index begins to climb steadily. At 7:00 AM, it registers a mild level of 2, but by 8:00 AM, it escalates to 4, indicating the start of a more intense sun exposure. The peak occurs at 11:00 AM and 12:00 PM, where it reaches a soaring 10, alerting everyone to take necessary precautions. After midday, the intensity starts to wane: it gently drops to 9 at 1:00 PM and gradually decreases to 5 by 3:00 PM. As the afternoon fades into evening, the UV Index dwindles to 3 at 4:00 PM and finally settles at 1 by 5:00 PM, bringing a close to the day's sun exposure risks. As night approaches, the UV Index drops to 0 after 7:00 PM, signifying a safe respite from the sun’s harsh rays.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | 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 | 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 |
The UV Index experiences significant seasonal variation, peaking during the summer months. March marks the start of heightened UV exposure with an index of 7, classifying it as high, while April and May see values rise to 8 and 9, respectively, both categorized as very high. The summer months of June and July maintain a UV Index of 10, followed by an intense peak of 11 in August, reaching the extreme category. These months represent the highest risk for sunburn, with recommended burn times decreasing to just 10-15 minutes. As the season transitions to fall in September, the UV Index decreases slightly to 9, but remains very high, making it essential for visitors and residents to take precautions, such as applying sunscreen and wearing protective clothing. By October, UV levels drop to 6 (high), and continue to decrease through the winter months, where January and December present moderate exposure with an index of 3. Overall, it’s crucial for everyone to stay informed and protect their skin during high-risk months from March to September.
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 |
| Seiro | 3 | 4 | 7 | 8 | 9 | 10 | 10 | 11 | 9 | 6 | 4 | 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 |