Last updated: August 1, 2025
In Niihama, Japan, awareness of the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels is essential not only to prevent painful sunburns but also to reduce the risk of long-term skin damage. Niihama's Cfa climate brings a mix of mild temperatures and varying UV exposure throughout the year, with peak indices reaching as high as 12 around noon. Being informed about these levels will help you enjoy the sunshine while protecting your skin's health—critical in a region where outdoor activities are abundant.
The UV Index data reveals a notable progression in sun exposure throughout the day. Starting at a modest 2 at 7:00 AM, it quickly escalates, peaking at a striking 12 by noon, indicating a high risk for harm from unprotected sun exposure. As the afternoon unfolds, the index gradually recedes, dropping to 9 at 2:00 PM and further decreasing to 1 by 7:00 PM. This pattern suggests that the sun’s intensity is at its most dangerous during the late morning and early afternoon, emphasizing the importance of sunscreen and protective measures during these critical hours. Stay safe under the sun!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | 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 | 6 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV radiation levels dramatically fluctuate, impacting the risk of skin damage for both visitors and residents. The highest risk months occur from May to August, where the UV Index peaks at 11 to 12, indicating an extreme exposure category with a burn time of just 10 minutes. During these months, it is crucial to limit direct sun exposure and utilize protective measures such as sunscreen, hats, and clothing to safeguard skin health. March and April also present high levels of concern, categorized as very high with burn times of just 15 minutes. As seasons shift into fall and winter, the UV Index decreases, with December and January showing a moderate level, allowing for longer safe exposure times of 30 minutes. However, even during lower UV months, protective precautions are still advised. Stay informed and protect yourself 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 |
| 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 |
| Niihama | 4 | 6 | 8 | 10 | 11 | 11 | 12 | 12 | 10 | 7 | 6 | 4 |