UV Index in Koshimizu, Japan

Last updated: July 2, 2025

Understanding the UV Index in Koshimizu, Japan is crucial for safeguarding your skin and overall health. With UV levels peaking at 10 during midday hours, awareness of these rates can help prevent sunburn and long-term skin damage. Koshimizu, characterized by its Dfb climate, can see its residents and visitors exposed to fluctuating UV exposure risks, especially during the summer months. By staying informed about the UV Index, you can enjoy the beautiful outdoors while keeping your skin protected.

Hourly UV Index in Koshimizu

As the sun rises, the UV Index steadily climbs, peaking at an impressive 10 between 11:00 and 12:00, signaling intense solar exposure. Starting at a mild 3 at 07:00, it quickly ramps up, reaching 7 by 09:00 and hitting 9 by 10:00. The intensity remains strong until 14:00, where it begins to taper off to 6 and then drops further to 4 and 2 in the late afternoon. As evening approaches, the UV Index dwindles to 1 by 17:00 and finally falls to 0 after 19:00. Stay protected during the peak hours, especially between 11:00 and 14:00, to enjoy the sunny day safely!

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	3	moderate	30 min
08:00	5	moderate	30 min
09:00	7	high	25 min
10:00	9	very high	15 min
11:00	10	very high	15 min
12:00	10	very high	15 min
13:00	8	very high	15 min
14:00	6	high	25 min
15:00	4	moderate	30 min
16:00	2	low	45 min
17:00	1	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Koshimizu

The UV Index exhibits significant seasonal fluctuations, with notable increases during the spring and summer months. From March to September, the UV Index reaches particularly high levels, marking May, June, July, August, and September as high-risk months for sun exposure. During this period, the UV Index often registers as very high (8 to 10), resulting in a reduced burn time of just 15 minutes. Residents and visitors should take precautionary measures, such as wearing protective clothing, applying sunscreen regularly, and seeking shade, especially when UV levels peak during the afternoon hours. In contrast, the winter months of January, February, October, November, and December present lower risks, with UV ratings between 2 and 5, allowing for longer safe exposure times. It is important to remain vigilant year-round, adjusting sun safety practices according to the changing UV Index.

Monthly Maximum UV Index for Koshimizu, Japan

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

The table above highlights how UV exposure in Koshimizu 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.

Koshimizu'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
Koshimizu	2	3	6	7	8	9	10	9	8	5	3	2
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