Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Honmachi, Japan, where the unique Dfc climate brings varied exposure to harmful ultraviolet rays throughout the year. Highly variable UV levels, peaking at 9 around midday, underscore the importance of being vigilant to prevent sunburn and protect overall skin health. With UV radiation being strongest between 10 AM and 2 PM, staying informed helps you enjoy the outdoors while safeguarding against the risks associated with prolonged sun exposure. Whether you're exploring the beautiful surroundings or simply enjoying a sunny day, knowing the UV Index is key to a safe and enjoyable experience in Honmachi.
The UV Index reflects the sun's intensity throughout the day, peaking at 11:00 AM with a maximum value of 9, indicating a high risk of harm from unprotected sun exposure. Starting from a gentle 3 at 07:00, the index rises steadily, reaching 8 by 10:00 AM and peaking at 9 just before noon. As the afternoon unfolds, the intensity begins to decline, dipping to 5 by 14:00, and further decreasing to a low of 1 by 17:00. The day wraps up with a 0 at 19:00, suggesting that the sun's rays pose little threat after sunset. Stay sun-safe by applying sunscreen during peak hours and seeking shade as needed!
| 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 | 8 | very high | 15 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 7 | high | 25 min |
| 14:00 | 5 | moderate | 30 min |
| 15:00 | 3 | 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 |
The UV Index varies significantly throughout the year, with high-risk months typically occurring from April to September, showcasing an index peaking at 10 in July. During these months, particularly in May through August, the exposure category is rated as very high with a burn time of just 15 minutes, signaling the need for heightened sun protection. Visitors and residents should be vigilant during this period, applying sunscreen regularly, wearing protective clothing, and seeking shade during peak sun hours. The index decreases in winter months, reaching a low of 2 in January and December, where protective measures can be relaxed, but moderation remains advisable to avoid any prolonged exposure even during low UV levels. Always check the local UV Index before heading outdoors, as conditions can change rapidly.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Honmachi | 2 | 3 | 5 | 7 | 8 | 9 | 10 | 9 | 8 | 5 | 3 | 2 |
| Sapporo UVI | 2 | 3 | 6 | 7 | 9 | 9 | 9 | 10 | 8 | 5 | 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 |