Last updated: June 2, 2025
In Hioki, Japan, awareness of the UV Index is crucial for maintaining skin health and preventing sunburn. As residents and visitors navigate the sunny days typical of this Cfa climate zone, understanding daily UV levels enables proactive measures for protection against harmful rays. With peak UV Index readings reaching as high as 12 during midday, it's essential to take precautions to safeguard your skin and enjoy the beautiful outdoors without the risks associated with prolonged sun exposure. Stay informed and stay safe!
As the sun rises, the UV Index begins its ascent, starting at a modest 2 at 07:00. By 08:00, it reaches 3, signaling the start of a day filled with increasing sun intensity. The index climbs to 6 by 09:00, peaking dramatically at 12 during noon. Between 11:00 and 13:00, the UV Index hovers around a remarkable 11, emphasizing the need for protection against the sun’s rays. As the afternoon rolls on, values gradually decline, settling at 9 by 14:00 and then tapering off to 7 at 15:00. By late afternoon, the index drops to 4 at 16:00 and continues its descent to 1 by the evening, reminding us of the dynamic nature of sunlight throughout the day. Stay informed and protected during the peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index levels show significant seasonal variations that pose varying risks of sunburn. January and December experience moderate exposure, with burn times of 30 minutes, while February sees a rise to high exposure (25 minutes). The spring months see a rapid escalation, peaking in March with a very high UV Index of 10 and a burn time of just 15 minutes. From April to August, the index remains at an extreme level, hitting its highest at 13 in August, where protection is vital as burn time drops to 10 minutes. As autumn arrives, September remains at extreme levels, but by October and November, the index decreases to very high and high, respectively. Residents and visitors are advised to take precautions, particularly during the high-risk months from March to September, by wearing sunscreen, protective clothing, and seeking shade to reduce exposure during peak hours.
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 |
| 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 |
| Hioki | 5 | 6 | 10 | 11 | 12 | 12 | 12 | 13 | 11 | 8 | 6 | 4 |