UV Index in Yamatokoriyama, Japan

Last updated: July 2, 2025

Understanding the UV Index in Yamatokoriyama, Japan is crucial for protecting your skin and overall health. With the potential for high UV exposure, particularly from late morning to early afternoon when values peak at 12, it's essential to be aware of the risks associated with sunburn and skin damage. As a part of the Cfa climate zone, Yamatokoriyama experiences warm summers, making it vital to monitor daily UV levels to ensure safe outdoor activities. By staying informed about UV Index readings, residents can take proactive steps to enjoy the sun safely while minimizing the risk of skin-related issues.

Hourly UV Index in Yamatokoriyama

The UV Index data for the day reveals a dynamic progression of sun exposure. Starting at a mild 2 at 07:00, the intensity of ultraviolet radiation ramps up, peaking sharply at 12 during noon. This is the key moment for sun safety, as the index indicates a very high risk of harm from unprotected sun exposure. As the afternoon unfolds, the index gradually decreases, dropping to 6 by 15:00, and then further wanes to 1 by 19:00, signaling a retreat from the sun's intensity. For those enjoying the outdoors, it's crucial to stay vigilant during the high points, particularly between 10:00 and 13:00, when sun protection is most essential.

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	4	moderate	30 min
09:00	7	high	25 min
10:00	10	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	1	low	45 min

Monthly UV Index Trends in Yamatokoriyama

Throughout the year, UV exposure varies significantly, with the highest risk occurring during the late spring and summer months. From April to August, the UV Index peaks at 11 to 12, representing an extreme exposure category, with a rapid burn time of just 10 minutes. Notably, March and September are also high-risk months, with UV Index levels of 8 and 10, respectively. To protect against harmful UV radiation, it is essential for both visitors and residents to take precautions during these peak months: seek shade, wear protective clothing, and apply broad-spectrum sunscreen regularly, especially between 10 AM and 4 PM. In contrast, during the winter months (January, December), UV levels drop to moderate, offering lower risk for skin damage, with longer burn times of 30 minutes.

Monthly Maximum UV Index for Yamatokoriyama, Japan

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

The table above highlights how UV exposure in Yamatokoriyama 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.

Yamatokoriyama'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
Yamatokoriyama	4	6	8	11	11	11	12	12	10	7	6	4