Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Kawagoe, Japan, especially during the peak sunlight hours. With the city experiencing a Cfa climate, where warm summers increase the risk of UV exposure, awareness of UV levels can significantly contribute to sunburn prevention and overall skin health. On sunny days, particularly between 10:00 AM and 12:00 PM, UV Index values can soar to 10, indicating a very high risk of harm from unprotected sun exposure. By staying informed about the UV Index, you can take proactive measures to enjoy the outdoors safely while protecting your skin from potential damage.
The UV Index shows a significant rise from 2 at 07:00 to a peak of 10 at 11:00 and 12:00, indicating the sun’s intensity is at its highest during these hours. As the day progresses, the index gradually declines, falling to 7 by 14:00 and dropping to 4 by 15:00. By late afternoon and evening, the UV exposure diminishes further, reaching 1 at 17:00 and 18:00, before tapering off to 0 by 19:00. This data emphasizes the importance of sun protection during the midday hours, particularly between 10:00 and 14:00, when UV radiation is most potent. Enjoy the sun responsibly!
| 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 | 4 | 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, the UV Index shows significant seasonal variations, indicating changes in the potential for skin damage. From January to February, the UV Index is moderate (3-5) with a burn time of 30 minutes. As March approaches, the UV Index rises sharply to 8, marking the beginning of high-risk months, which continue through July when it peaks at 11 (extreme exposure). The highest risk persists until August with UV levels remaining very high. From September to October, the index gradually declines to 7 and 5, transitioning back to moderate levels by November and December. Visitors and residents should exercise caution during high-risk months (March to August), limiting sun exposure, and using protective measures like sunscreen and clothing to prevent skin damage. Regular monitoring of UV levels is advisable, especially in the peak summer months when the risks are greatest.
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 |
| Kawagoe | 3 | 5 | 8 | 9 | 10 | 10 | 11 | 10 | 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 |