Last updated: July 2, 2025
In Toyohama, Japan, awareness of the UV Index is crucial for everyone seeking to protect their skin from harmful solar radiation. Understanding UV levels is vital for preventing sunburn and maintaining long-term skin health, especially in a region that experiences significant sun exposure due to its Cfa climate, characterized by hot summers and mild winters. During peak hours, especially between 10 AM and 2 PM, the UV Index can reach alarming levels, peaking at 12, which underscores the importance of sun safety practices—whether it's applying sunscreen, wearing protective clothing, or seeking shade. Stay informed and safeguard your skin against the risks of UV exposure!
The UV Index for the day reveals a dynamic trajectory of sun intensity, peaking at 12 around noon. From the early hours, starting at 2 at 7:00 AM, the index climbs steadily, reaching 7 by 9:00 AM. As the sun reaches its zenith, the UV levels soar, hitting their maximum of 11 at 11:00 AM and remaining incredibly high at 12 from 12:00 PM to 1:00 PM. However, as the afternoon progresses, the index begins to decline, tapering down to 8 at 2:00 PM and further decreasing to 6 by 3:00 PM. By the evening, the UV Index drops significantly, settling back to 2 at 5:00 PM and finally waning to a calming zero by 7:00 PM. It's a day to stay sun-smart, especially during those peak midday hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 10 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV exposure varies significantly, with the highest risk typically occurring from March to September. During this period, the UV Index reaches its maximum, peaking at 12 in July, categorizing it as extreme, with a minimum burn time of just 10 minutes. April and May also present high-risk months, with UV Index values of 10 and 11, respectively. As a result, residents and visitors are advised to take precautions, including frequent application of sunscreen, wearing protective clothing, and seeking shade, particularly during midday hours when the sun's rays are strongest. In contrast, winter months see a decline in UV levels, with January to February falling into the moderate exposure category, while October provides a brief respite at a high level but still requires attention. Staying informed and proactive can help ensure safety from harmful UV radiation throughout the seasons.
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 |
| Toyohama | 4 | 5 | 8 | 10 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |