Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Itoshima, Japan, where the subtropical climate can bring intense sun exposure. Being aware of UV levels not only helps in preventing sunburn but is also vital for maintaining overall skin health throughout the year. Itoshima often experiences high UV readings, especially between 10 AM and 2 PM, with peak values reaching 12—the intensity that can significantly increase risks of skin damage. By staying informed about the UV Index, you can enjoy the beautiful beaches and outdoor activities while protecting your skin from harmful rays.
During the morning hours, the UV Index starts off low at 1 at 7:00 AM, indicating minimal risk of harm from unprotected sun exposure. As the day progresses, the intensity ramps up, peaking at 12 around 12:00 PM and 1:00 PM, suggesting a high risk for harm, especially for those spending extended periods outdoors. Post-peak, the index gradually declines, dropping to 7 at 3:00 PM and further down to 1 by 7:00 PM, which indicates a return to minimal risk as the sun sets. For sun enthusiasts, midday offers the most intense UV radiation, making sun protection essential during those 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 | 12 | 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, 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 |
Itoshima | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 12 | 11 | 7 | 6 | 4 |