Last updated: May 3, 2025
In Itoigawa, Japan, staying aware of the UV Index is crucial for ensuring skin health and preventing sunburn. With the region's Cfa climate, residents and visitors alike experience varying levels of UV exposure throughout the day, peaking at a height of 10 between 11:00 AM and 12:00 PM. Understanding these UV levels is essential, as even brief sun exposure at these times can lead to skin damage. By tracking the UV Index, you can take proactive steps to protect yourself and enjoy the beautiful Itoigawa landscape safely.
At sunrise, the UV Index starts at a gentle 2 at 7:00 AM, gradually climbing to a moderate 4 by 8:00 AM. As the day progresses, the sun's intensity peaks with a striking 10 at both 11:00 AM and 12:00 PM, indicating a high risk of harm from unprotected sun exposure. By 1:00 PM, the index remains strong at 9, but starts to decline to 7 by 2:00 PM. Early afternoon light gives way to a safer environment as the index sinks to 5 at 3:00 PM, then further drops to 3 by 4:00 PM. As the sun sets, the UV Index descends into the low range, resting at 1 by 5:00 PM and tapering off to 0 after 7:00 PM—a clear reminder to protect your skin during those peak sun hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 8 | 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 |
Throughout the year, UV Index values experience significant seasonal changes, indicating varying levels of sun exposure risk. January and December have moderate UV Indexes (3), suggesting a safer exposure time of 30 minutes. As we move into February and November, the UV Index rises to 5, still moderate, but caution is warranted with a similar burn time. From March to October, the UV Index escalates, reaching its peak between July and August at an extreme level of 11, where only a mere 10 minutes of exposure can lead to burns. April and May also present very high risk with indexes of 9 and 10, respectively, offering 15 minutes of allowed exposure. The fall months, including September with a UV Index of 9, still require vigilance. Visitors and residents are urged to take necessary precautions during high-risk months—especially from March through August—to protect their skin, such as seeking shade, wearing protective clothing, and applying broad-spectrum sunscreen regularly.
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 |
| Itoigawa | 3 | 5 | 7 | 9 | 10 | 10 | 11 | 11 | 9 | 6 | 5 | 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 |