Last updated: July 2, 2025
Understanding the UV Index in Iwanuma, Japan, is crucial for protecting your skin and overall health. With UV levels peaking at 10 during midday—significantly increasing the risk of sunburn—awareness of these values can empower residents and visitors to take necessary precautions. Iwanuma's Cfa climate, characterized by warm summers, often leads to heightened UV exposure, making it essential to monitor these levels daily. Safeguarding against harmful UV rays not only helps prevent skin damage but also promotes long-term skin health, ensuring that you enjoy the beautiful sunny days in Iwanuma safely.
The UV Index for the day starts off gently at 3 by 7:00 AM, gradually elevating as the sun climbs higher in the sky. By 9:00 AM, it reaches 7, signaling the onset of stronger rays. The peak occurs between 11:00 AM and 12:00 PM, where it hits a maximum of 10, indicating a high risk of harm from unprotected sun exposure. As the afternoon progresses, the index starts to decline, dipping to 5 by 3:00 PM and further to 1 by 5:00 PM, leading to a comfortable evening. As night falls at 7:00 PM, the UV index drops to 0, marking the end of sun-related concerns for the day. Remember to take precautions during peak hours to protect your skin!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
As the seasons change, so does the UV Index, significantly impacting sun exposure and the risk of skin damage. From January to February, the UV Index is moderate (3-4) with a longer burn time of 30 minutes. However, as we transition into March and April, the UV Index rises sharply to high (7) and very high (8) respectively, with burn times decreasing to just 25 and 15 minutes. The peak UV intensity occurs during the summer months of July and August when the Index reaches an extreme level of 11, with a mere 10 minutes for potential sunburn. Visitors and residents should be particularly cautious from March through September, the high-risk months for UV exposure, and take proactive measures such as applying sunscreen, wearing protective clothing, and seeking shade during peak hours to minimize skin damage. As the year concludes, the UV levels drop again in October to moderate levels in November and December, providing a respite from intense sun exposure.
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 |
| Iwanuma | 3 | 4 | 7 | 8 | 10 | 10 | 11 | 10 | 9 | 6 | 4 | 3 |
| 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 |