UV Index in Koshi, Japan

Last updated: May 3, 2025

In Koshi, Japan, being aware of the UV Index is crucial for maintaining your skin health under the region's varied climate, classified as Cfa. Understanding UV levels can help in preventing sunburn and reducing the risk of long-term skin damage. With peak UV readings reaching as high as 11 around midday, residents and visitors alike should take care to protect themselves during those hours. As Koshi experiences fluctuating UV exposure throughout the day—starting from a mild 2 at sunrise and nearing its maximum intensity at 12 PM—it's vital to stay informed and prepared to enjoy the sun safely!

Hourly UV Index in Koshi

The UV Index today showcases a dynamic rise and fall throughout the hours, peaking at 11 from 12:00 PM to 1:00 PM. Starting from a gentle 2 at 7:00 AM, it climbs steadily, reaching 10 by 11:00 AM. As the sun approaches its zenith, the index hits its maximum of 11, indicating a high risk of harm from unprotected sun exposure. After this peak, the index begins its descent, tapering down to 6 at 3:00 PM before declining further to 2 by 5:00 PM. As evening sets in, it settles at a mild 1 from 6:00 PM onward, reminding us to take precautions when basking in the midday sun but allowing for safer outdoor activities as daylight fades.

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	8	very high	15 min
11:00	10	very high	15 min
12:00	11	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 Koshi

Throughout the year, the UV Index exhibits significant seasonal variations, with spring and summer months posing the highest risk of UV exposure. From March to September, the index reaches very high to extreme levels—particularly during April to August, where it peaks at 12 in July and August. During these months, the burn time shortens dramatically to just 10 minutes, indicating a critical need for sun protection. Conversely, January and December record the lowest UV levels with a moderate exposure category, allowing for more extended exposure times of 30 minutes. Visitors and residents are advised to take precautions, especially from March to September, by wearing protective clothing, applying sunscreen, and seeking shade during peak hours to minimize the risks associated with high UV exposure.

Monthly Maximum UV Index for Koshi, Japan

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

The table above highlights how UV exposure in Koshi 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.

Koshi'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
Koshi	4	6	8	11	11	11	12	12	11	8	6	4