Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Ijuin, Japan, where the Cfa climate brings a mix of temperate weather and varying sun exposure. Being aware of UV levels helps protect against sunburn and long-term skin damage, ensuring your skin stays healthy and vibrant. During peak hours, particularly from 10 AM to 1 PM, the UV Index can soar to 13, indicating a high risk for harm from unprotected sun exposure. With Ijuin's sunny days, it’s essential to stay informed and take proactive measures against harmful rays to enjoy the beautiful outdoors safely.
The UV Index for the day exhibits a striking daytime peak, rising steadily from a gentle 1 at 07:00 to an intense 13 by 12:00. As the sun reaches its zenith, the 11:00 and 12:00 hours warn of heightened exposure, with the index hitting its maximum at 13:00 before beginning its gradual decline. By 15:00, it slips to 7, reminding us that even in the afternoon, protection is vital. As the day winds down, the UV levels fall back to a safe 1 by 18:00, ensuring a return to safer conditions for evening activities. Stay vigilant and protect your skin during those midday hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 10 | 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 |
| Ijuin | 5 | 6 | 10 | 11 | 12 | 12 | 12 | 13 | 11 | 8 | 6 | 4 |