Last updated: May 3, 2025
Understanding the UV Index is essential for residents and visitors in Honjo, Japan, where sun exposure can vary dramatically throughout the day. With typical summer conditions in this Cfa climate zone, awareness of UV levels helps prevent sunburn and maintain long-term skin health. The midday UV Index can peak at 10, indicating high risk for harm from unprotected sun exposure. By staying informed about the UV Index, you can make informed decisions about outdoor activities and protect your skin from potential damage. Whether enjoying the sunlit parks or exploring the local scenery, remember to check the UV Index to keep your skin safe!
The UV Index paints a vivid picture of the sun's intensity throughout the day. Starting at 7:00 AM with a gentle 2, the warmth gradually increases, peaking at 11:00 AM and 12:00 PM with a maximum index of 10, indicating a very high risk of harm from unprotected sun exposure. As the afternoon progresses, the intensity starts to wane, dropping to 9 at 1:00 PM and gradually decreasing to 5 by 3:00 PM. By the late afternoon, the index falls back into the comfortable zones of 2 at 4:00 PM and 1 by 5:00 PM, before finally settling at 0 as dusk arrives at 7:00 PM. This fluctuation underscores the importance of sun safety measures, particularly during the midday hours when the sun is at its fiercest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 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 | 5 | 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, UV levels demonstrate significant seasonal variations, with high-risk months typically occurring from March through August. During this period, the UV Index peaks at 11 in June, July, and August, marking it as an extreme risk category with a burn time of just 10 minutes. In contrast, the lowest UV Index readings, categorized as moderate, occur in January, February, November, and December, allowing for 30-minute exposure without immediate risk of skin damage. Visitors and residents should prioritize sun safety measures, particularly in the high-risk months—using sunscreen, wearing protective clothing, and seeking shade during peak hours to minimize potential harm from intense UV radiation.
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 |
| Honjo | 3 | 5 | 8 | 9 | 10 | 11 | 11 | 11 | 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 |