UV Index in Kumamoto, Japan

Last updated: July 2, 2025

In Kumamoto, Japan, staying informed about the UV Index is crucial for protecting your skin and overall health. With daily UV levels fluctuating significantly—peaking at 13 around noon—awareness can be the key to preventing sunburn and long-term skin damage. The Cfa climate in Kumamoto, characterized by hot and humid summers, often brings high UV exposure, making it essential to understand when and how to safeguard yourself while enjoying the outdoors. By keeping an eye on UV levels, you empower yourself to enjoy sunny days responsibly and protect your skin from harmful effects.

Hourly UV Index in Kumamoto

The UV Index exhibits a dynamic range throughout the day, starting at a mild level of 2 at 7:00 AM. As the sun rises higher, it peaks at an intense 13 by 12:00 PM, indicating a significant risk of harm from unprotected sun exposure. From there, it begins a gentle decline, dropping to 10 at 2:00 PM and gradually tapering off to 1 by the evening hours. The highest figures, 11 and 13, underscore the importance of applying sunscreen and wearing protective clothing during midday. As the day unfolds, be sure to take precautions during peak UV hours to ensure your safety in the sun!

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
Time	UVI	Category	Time to Burn
07:00	2	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	13	extreme	10 min
13:00	12	extreme	10 min
14:00	10	very high	15 min
15:00	7	high	25 min
16:00	4	moderate	30 min
17:00	2	low	45 min
18:00	1	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Kumamoto

Throughout the year, the UV Index shows notable seasonal changes, with the highest risk occurring from March to September. During these months, the index reaches extreme levels, particularly peaking in August with a UV Index of 13. Visitors and residents should exercise caution during high-risk months and, ideally, limit direct sun exposure to less than 10 minutes daily between April and September. In contrast, the UV Index is relatively moderate in January and December, with burn times of 30 minutes. To minimize the risk of skin damage, it is essential to apply sunscreen, wear protective clothing, and seek shade, especially during peak hours from late morning to early afternoon.

Monthly Maximum UV Index for Kumamoto, Japan

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Kumamoto. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Kumamoto, based on information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

Compare Kumamoto UV Index with Other Japan Cities

The table above highlights how UV exposure in Kumamoto compares to other major locations across Japan. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

Kumamoto's solar exposure compared to other cities in Japan. Generated using Copernicus Atmosphere Monitoring Service information.
	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
Kumamoto	5	6	9	11	12	12	12	13	11	8	6	4