Last updated: May 3, 2025
In Arai, Japan, staying informed about the UV Index is crucial for safeguarding your skin health and preventing sunburn. With a humid subtropical climate (Cfa), Arai experiences varying UV levels throughout the day, peaking at an intense 10 between 11:00 AM and 12:00 PM. Understanding these fluctuations can help you take proactive measures against harmful UV rays, ensuring your time outdoors is both enjoyable and safe. As the sun rises to its zenith, being aware of the UV index allows you to plan your activities wisely and protect yourself against skin damage.
The UV Index paints a vivid picture of the sun’s intensity throughout the day. At sunrise (07:00), the index starts modestly at 2, but by 08:00, it rises to a comfortable 4. The sun gains strength, with readings escalating to 6 by 09:00. The peak arrives at 11:00 and 12:00, where the index reaches a striking 10—a clear signal to seek shade or apply sunscreen! As the afternoon progresses, we see a decline; the UV Index drops to 9 at 13:00 and gradually decreases to 5 by 15:00. The late afternoon brings a gentle taper off to 3 by 16:00, before plummeting to 1 by 17:00 and finally settling at 0 as evening descends (19:00). Stay sun-smart and enjoy the daylight safely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | 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 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index exhibits significant seasonal variation, peaking during the summer months. High-risk months, particularly from March to August, see the UV Index reach extremes, with levels of 8 to 11 categorized as very high to extreme, resulting in quick burn times ranging from 10 to 15 minutes. Visitors and residents should take precautions during these months by seeking shade, wearing protective clothing, and applying sunscreen to minimize sun exposure. The UV levels decrease from September to November, but caution is still advised, especially with a moderate UV Index in the cooler months. Stay informed and protect your skin to enjoy the outdoors safely year-round.
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 |
| Arai | 3 | 5 | 8 | 9 | 10 | 11 | 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 |