Last updated: May 3, 2025
In Choshi, Japan, being vigilant about the UV Index is essential for maintaining skin health and preventing sunburn. With its Cfa climate, Choshi experiences vibrant summers that can lead to significant UV exposure, especially during peak hours when the index reaches levels as high as 11. Understanding these UV levels empowers locals and visitors alike to take proactive measures against harmful rays, ensuring a safer and more enjoyable time under the sun. As you navigate your day in Choshi, keep an eye on the UV Index to shield yourself from the sun's intensity and protect your skin.
As the sun rises, the UV Index begins a steady ascent, starting at a moderate 3 by 7:00 AM. By 8:00 AM, it climbs to 5, catching the attention of early risers. The intensity peaks dramatically at 10:00 AM, hitting a blistering 10, and remains at its highest at 11:00 AM and 12:00 PM with a value of 11. As the afternoon unfolds, the index slowly retreats, dipping to 9 at 1:00 PM and further to 7 by 2:00 PM. By the time the sun begins its descent, the numbers dwindle to 4 at 3:00 PM, and taper off to a gentle 1 by 5:00 PM, disappearing entirely by 7:00 PM. This hourly fluctuation underscores the importance of sun protection during those peak hours, especially when the UV Index soars. Remember to stay safe and shield yourself during the hottest times of the day!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 8 | very high | 15 min |
| 10:00 | 10 | 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 | 4 | moderate | 30 min |
| 16:00 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV exposure varies significantly, with the highest levels occurring during the summer months. From March to August, the UV Index reaches a peak of 11 during May, June, and July, classified as extreme with a burn time of just 10 minutes. Notably, April and August also present very high levels, indicative of a higher risk for skin damage. Visitors and residents are advised to take extra precautions during these months by seeking shade, wearing protective clothing, and applying sunscreen frequently. Conversely, the risk is lower in the winter months, with the UV Index ranging from 3 to 5 from January to February and returning to similar levels in November and December. Awareness of these seasonal changes is crucial to ensure appropriate sun safety measures are taken year-round.
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 |
| Choshi | 3 | 5 | 8 | 10 | 11 | 11 | 11 | 10 | 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 |