Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Marumori, Japan, where the subtropical Cfa climate can lead to significant sun exposure. Being aware of UV levels helps protect against sunburn and long-term skin damage, making it vital for your health. With midday UV Index readings soaring as high as 10, outdoor activities in the summer months can pose serious risks if proper precautions aren’t taken. Whether you’re enjoying a stroll in the sun or working outside, knowing when to seek shade or apply sunscreen can make all the difference in safeguarding your skin health. Stay informed and enjoy the summer safely in vibrant Marumori!
The UV Index climbs steadily throughout the morning, peaking at a maximum of 10 at 11:00 AM. Early risers will notice a moderate 3 at 07:00, but by 08:00, it escalates to a higher 5. The sun takes center stage by 09:00, reaching 7, and by the time it's 10:00, it soars to a 9. As the clock strikes 11:00 AM, sun worshippers should take heed as the index hits its highest point. After lunchtime, the UV Index begins to descend gracefully, dropping to 8 at 1:00 PM and further declining to 6 at 2:00 PM. By late afternoon, it falls to 4 at 3:00 PM, quickly diminishing to a mere 1 by 5:00 PM, before concluding with a safe 0 at 7:00 PM. Always remember to protect your skin during those peak hours!
| 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 | 10 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 6 | 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 |
As the seasons change, so does the UV Index, significantly impacting sun exposure and the risk of skin damage. From January to February, the UV Index is moderate (3-4) with a longer burn time of 30 minutes. However, as we transition into March and April, the UV Index rises sharply to high (7) and very high (8) respectively, with burn times decreasing to just 25 and 15 minutes. The peak UV intensity occurs during the summer months of July and August when the Index reaches an extreme level of 11, with a mere 10 minutes for potential sunburn. Visitors and residents should be particularly cautious from March through September, the high-risk months for UV exposure, and take proactive measures such as applying sunscreen, wearing protective clothing, and seeking shade during peak hours to minimize skin damage. As the year concludes, the UV levels drop again in October to moderate levels in November and December, providing a respite from intense sun 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 |
| Marumori | 3 | 4 | 7 | 8 | 10 | 10 | 11 | 10 | 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 |