Last updated: July 2, 2025
In Hatsukaichi, Japan, awareness of the UV Index is crucial for ensuring healthy skin and preventing sunburn. With a climate characterized by humid subtropical conditions, local residents and visitors alike face varying levels of UV exposure throughout the day. Understanding UV levels can guide you in taking essential precautions, especially during peak hours when the index soars to a maximum of 12 around noon. As the sun's rays can be particularly intense in this region, staying informed about the UV Index will help protect your skin from damage and promote long-term health. Remember, whether you're exploring the stunning landscapes or enjoying outdoor activities, being savvy about UV levels is key to a safe and enjoyable experience.
The UV Index throughout the day showcases a dynamic shift in sun intensity, peaking at 12 around noon. Beginning with a gentle 2 at 7:00 AM, the index steadily increases, hitting 11 by 11:00 AM as the sun climbs higher. By 12:00 PM, the sun reaches its zenith at 12, marking the highest UV exposure, making sun safety a priority. As the afternoon progresses, from 1:00 PM to 3:00 PM, the UV Index gradually decreases to 9 by 2:00 PM and 7 by 3:00 PM. The day winds down with a notable drop in intensity, returning to a mild 1 by 6:00 PM, emphasizing that the safest time to enjoy the sun is before noon or after 4:00 PM.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | 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 | 11 | extreme | 10 min |
| 14:00 | 9 | 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, UV Index levels exhibit significant seasonal variation, with the highest risks occurring in the spring and summer months. From March to August, the UV Index reaches extreme levels, peaking at 12 in July and August, where the recommended burn time is just 10 minutes. The months of April and May also maintain an extreme UV Index of 11. Conversely, during January and December, UV exposure is at a moderate level with a UV Index of 4, allowing for a burn time of 30 minutes. For residents and visitors, it is crucial to be particularly cautious from March through September, taking protective measures like wearing sunscreen, protective clothing, and limiting sun exposure during peak hours. Remain vigilant and prioritize skin safety, especially during the high-risk months of April through August.
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 |
| Hatsukaichi | 4 | 5 | 8 | 11 | 11 | 11 | 12 | 12 | 10 | 7 | 6 | 4 |