Last updated: July 2, 2025
In Karasuyama, Japan, understanding the UV Index is crucial for protecting your skin and maintaining overall health. With peak UV levels soaring to 11 around midday, awareness is key to preventing sunburn and long-term skin damage. The temperate Cfa climate of Karasuyama brings varied weather, but the intense UV exposure—particularly during summer months—can pose significant risks if left unmonitored. By keeping an eye on the UV index, you empower yourself to enjoy the outdoors safely while prioritizing your skin's well-being.
The hourly UV Index reveals a dynamic rise and fall of sun intensity throughout the day. Starting at a mild 2 at 07:00, the index climbs steadily, reaching a peak of 11 at both 11:00 and 12:00, indicating a high risk of harm from unprotected sun exposure. As the afternoon sun begins to descend, the index tapers off to 9 at 13:00, then gradually decreases to 5 by 15:00. By 16:00, it drops to 3, signaling the end of peak sun strength, while cool evenings arrive with a return to 1 at both 17:00 and 18:00. Finally, at 19:00, the UV Index hits 0, marking a safe transition into the night. Stay protected during the day's brightest hours!
| 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 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 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, UV Index values experience significant seasonal changes, indicating varying levels of sun exposure risk. January and December have moderate UV Indexes (3), suggesting a safer exposure time of 30 minutes. As we move into February and November, the UV Index rises to 5, still moderate, but caution is warranted with a similar burn time. From March to October, the UV Index escalates, reaching its peak between July and August at an extreme level of 11, where only a mere 10 minutes of exposure can lead to burns. April and May also present very high risk with indexes of 9 and 10, respectively, offering 15 minutes of allowed exposure. The fall months, including September with a UV Index of 9, still require vigilance. Visitors and residents are urged to take necessary precautions during high-risk months—especially from March through August—to protect their skin, such as seeking shade, wearing protective clothing, and applying broad-spectrum sunscreen regularly.
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 |
| Karasuyama | 3 | 5 | 7 | 9 | 10 | 10 | 11 | 11 | 9 | 6 | 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 |