Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Izu, Japan, as it serves as a vital tool in safeguarding your skin health. With its Cfa climate, Izu typically experiences significant sun exposure, particularly during the midday hours when the UV Index peaks at a striking 12. This level of UV exposure can rapidly lead to sunburn and long-term skin damage if proper precautions are not taken. By familiarizing yourself with daily UV levels, especially between 10:00 AM and 2:00 PM, you can effectively protect yourself from harmful rays and enjoy all that Izu has to offer while keeping your skin safe.
The UV index today begins with a gentle rise, starting at a modest 2 at 7:00 AM. As the sun climbs higher, it reaches 5 by 8:00 AM, quickly escalating to a peak 12 by both 11:00 AM and 12:00 PM—indicating the highest intensity of UV radiation. From that point, the index starts to decline, dropping to 11 at 1:00 PM, and then gently easing down to 8 by 2:00 PM. The afternoon watches the UV levels further retreat to 6 at 3:00 PM, finally tapering off to a cool 1 by 5:00 PM, settling to 0 by 7:00 PM. It's a day where early sun seekers must take care, especially during the midday hours.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 8 | very high | 15 min |
| 10:00 | 10 | very high | 15 min |
| 11:00 | 12 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 6 | high | 25 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 |
Throughout the year, the UV Index demonstrates notable seasonal changes, with the most intense exposure occurring from April to August. During these months, the UV Index reaches extreme levels (10-12), significantly reducing the burn time to just 10 minutes. March and September also pose risks with very high levels (8-10), allowing for a burn time of only 15 minutes. Consequently, February and October present high levels (6-7), where protective measures are still advised with adjusted burn times of 25 minutes. Residents and visitors should exercise caution and protect their skin, especially during the high-risk months of April through August, by using sunscreen, wearing protective clothing, and limiting sun 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 |
| Izu | 4 | 6 | 8 | 10 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 4 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |