Last updated: June 2, 2025
Understanding the UV Index in Sendai, Japan, is crucial for safeguarding your skin and overall health. With maximum UV levels surging to 11 during midday hours, knowledge of these values can empower residents and visitors alike to take necessary precautions against harmful sun exposure. Skin health is at stake, as even short periods of high UV exposure can lead to painful sunburns and long-term damage. Sendai’s Cfa climate means warm summers and moderate winters, but the sun's intensity, especially during peak hours, poses unique risks. Stay informed and enjoy the sun safely!
As the day unfolds, the UV Index climbs steadily, peaking at 11 between 11:00 and 12:00, signaling a strong need for sun protection during these hours. Starting from a mild 3 at 07:00, the intensity rapidly rises, reaching a noticeable 5 by 08:00 and soaring to 9 by 10:00. However, the sun's intensity begins to wane in the afternoon, dropping to 7 and then 5 from 13:00 to 15:00. By 16:00, the UV Index retreats to 3, and as evening sets in, it diminishes further to 1 by 17:00 and falls to 0 by 19:00. It's crucial to stay vigilant during those peak hours to enjoy the sun safely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 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, impacting both visitors and residents. From January to February, the UV Index remains at a moderate level (3-4), allowing for 30 minutes of sun exposure without significant risk. However, as spring approaches in March, the index climbs to high (7), reducing safe exposure to 25 minutes. The peak UV Index occurs during summer months, notably in July and August, where it reaches an extreme level (11) with a mere 10 minutes of safe exposure. September sees a decline to very high (9), while October returns to high (6) conditions, each allowing for a bit more time in the sun—25 minutes and 15 minutes respectively. From November to December, the UV risks lower again to moderate (3-4), allowing for 30 minutes. Visitors and residents should be especially cautious from March through September, particularly during peak summer months, by applying sunscreen, wearing protective clothing, and limiting sun exposure 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 |
| Sendai | 3 | 4 | 7 | 8 | 10 | 10 | 11 | 11 | 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 |