Last updated: July 2, 2025
Understanding the UV Index is essential for residents and visitors of Honcho, Japan, where the risk of sun exposure varies significantly throughout the day. Keeping an eye on UV levels is crucial for preventing sunburn and maintaining long-term skin health, especially during the peak hours when the index reaches as high as 10 around noon. Honcho's Dfb climate brings distinct seasonal changes, resulting in varying UV exposure risks; thus, being informed can help you enjoy the beautiful outdoors while protecting your skin. Stay vigilant about the UV Index to ensure safe sun practices!
As the sun rises, the UV Index begins to climb, starting at a moderate 3 by 7:00 AM. By 8:00 AM, it reaches 4, signaling a steady increase in solar intensity. The peak occurs at 12:00 PM with a soaring 10, indicating a high risk of harm from unprotected sun exposure. Although it dips to 8 by 1:00 PM, the midday sun remains potent. The afternoon brings a gradual decline, falling to 5 at 3:00 PM, before tapering off to an evening low of 1 by 5:00 PM and remaining steady through 7:00 PM. Remember to take precautions during those peak hours! Safe sunning! 🌞
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 8 | 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 | 1 | low | 45 min |
Throughout the year, UV radiation levels change significantly, affecting the risk of sunburn for visitors and residents. The highest UV Index occurs during August, with an extreme rating of 11, resulting in a rapid burn time of just 10 minutes. From April to September, UV exposure is particularly hazardous, with several months categorized as very high to extreme. Notable high-risk months include April (UV Index 8), May (UV Index 9), and June and July (UV Index 10), all requiring vigilant sun protection measures. Residents and visitors are advised to limit sun exposure, especially during peak hours, seek shade, and wear protective clothing and sunscreen to safeguard against harmful UV rays. As the year progresses into fall and winter, the UV Index decreases, offering more manageable levels of exposure, but caution is still advised during the transitional months of October (UV Index 6) and November (UV Index 3).
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 |
| Honcho | 2 | 4 | 5 | 8 | 9 | 10 | 10 | 11 | 8 | 6 | 3 | 2 |
| 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 |