Last updated: June 2, 2025
Understanding the UV Index in Shimabara, Japan, is essential for maintaining skin health and preventing harmful sunburns. With UV levels peaking at a considerable 11 during midday hours, awareness of these fluctuations can help residents and visitors alike take proactive measures against overexposure. Shimabara's Cfa climate provides ample sunny days, making it crucial to monitor UV intensity, especially from late morning to early afternoon when the sun's rays are most potent. Stay informed about the UV Index to safeguard your skin while enjoying the beautiful landscapes and vibrant culture of this unique coastal town.
The UV Index throughout the day presents a notable peak between 11:00 AM and 1:00 PM, where it reaches a striking 11, indicating a high risk for harm from unprotected sun exposure. The intensity starts at a lower 2 at 7:00 AM, gradually climbing to 3 by 8:00 AM before skyrocketing to 10 by 11:00 AM. As the midday sun intensifies, it maintains a level of 11 at both 12:00 PM and 1:00 PM, prompting a reminder to seek shade and wear protective gear. The afternoon sees a decline, dipping to 9 at 2:00 PM and gradually tapering off to 4 by 4:00 PM, then further down to 2 at 5:00 PM. As evening approaches, the levels drop to a gentle 1 by 6:00 PM, highlighting the importance of being sun-aware, especially during those 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 | 10 | very high | 15 min |
| 12:00 | 11 | 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, seasonal changes in UV exposure highlight periods of heightened risk for residents and visitors. From January to February, the UV Index rises from 4 (moderate) to 6 (high), reducing safe exposure time to 25 minutes. Significant increases occur in March, reaching 8 (very high), and peaking during the summer months of April to August at 11-12 (extreme), where only 10 minutes of unprotected exposure is advisable. The risk, while still present, decreases again in September and returns to high levels in October and November with a UV Index of 6-7, allowing for 25 minutes of safe exposure. As such, it is crucial for visitors and residents to remain vigilant, especially during the summer, taking precautions like wearing sunscreen, protective clothing, and seeking shade during peak hours to mitigate the risk of UV-related health issues.
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 |
| Shimabara | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 12 | 11 | 7 | 6 | 4 |