UV Index in Nankoku, Japan

Last updated: August 1, 2025

Understanding the UV Index in Nankoku, Japan, is crucial for safeguarding your skin health and preventing sunburn. With the region's Cfa climate, characterized by warm summers and varying sunlight exposure, being aware of UV levels can help you enjoy outdoor activities responsibly. The UV Index peaks at a staggering 12 around midday, posing significant risks if protective measures aren’t taken. By staying informed about these levels, you can take proactive steps to enjoy the beautiful, sun-drenched days of Nankoku while keeping your skin safe and healthy.

Hourly UV Index in Nankoku

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!

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	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

Monthly UV Index Trends in Nankoku

Throughout the year, the UV Index experiences significant fluctuations, with the highest risk months occurring from March to August, where it often reaches extreme levels. Notably, April, May, June, July, and August all register a UV Index of 12, indicating critical exposure levels with a burn time of only 10 minutes. Visitors and residents should take precautions during these months, such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours. Conversely, from January to February and October to November, the UV levels are lower, categorized as moderate to high, allowing for a more comfortable outdoor experience, although caution is still advised. In December, the UV Index drops back to 4, reverting to a moderate category where burn time extends to 30 minutes, making it the safest month for outdoor activities. Overall, awareness of the UV Index can help individuals protect themselves from harmful sun exposure year-round.

Monthly Maximum UV Index for Nankoku, Japan

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Nankoku. 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 Nankoku, 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 Nankoku UV Index with Other Japan Cities

The table above highlights how UV exposure in Nankoku 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.

Nankoku'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
Nankoku	4	6	9	11	11	12	12	12	10	7	6	4