Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Chikusei, Japan, where the Cfa climate can lead to significant UV exposure, especially during peak hours. Being aware of daily UV levels helps in preventing sunburn and maintaining long-term skin health. From the early morning hours when UV levels begin to rise, peaking at 10 around noon, the risk of harmful skin damage increases. With this knowledge, you can take proactive steps to protect yourself under the sun, ensuring that outdoor activities remain safe and enjoyable year-round.
The UV Index rises sharply from the early morning, peaking at 10 between 11:00 and 12:00, signaling intense sun exposure. As the day unfolds, 08:00 sees a jump to 5, while 09:00 and 10:00 bring increasing values of 7 and 9, respectively. The afternoon hours witness a gentle decline, with the index easing to 9 at 13:00 before dropping to 7 at 14:00. By the time the evening arrives, the UV levels decrease significantly, resting at 5 by 15:00, further declining to just 1 by 17:00, and tapering off to 0 after 19:00. To ensure safety during peak hours, it’s advisable to seek shade and wear protective clothing, especially between 11:00 and 12:00 when the sun is most potent.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 5 | 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 |
The seasonal changes in UV Index reveal significant variations throughout the year, with the highest levels occurring in the summer months. March marks the transition into the high-risk category with a UV Index of 7, and by April and May, it escalates to 9 and 10 respectively, indicating very high levels of UV radiation. July reaches its peak at an extreme level of 11, posing the highest risk for skin damage with a burn time of only 10 minutes. Post-summer in August and September, UV levels remain notably high, while October drops to a high level of 6, still warranting caution. January, February, November, and December exhibit moderate UV levels, with burn times allowing for more extended exposure without burns. For both visitors and residents, it is vital to take protective measures during the high-risk months of March to September, including wearing sunscreen, protective clothing, and seeking shade during peak hours to minimize UV 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 |
| Chikusei | 3 | 5 | 7 | 9 | 10 | 10 | 11 | 10 | 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 |