UV Index in Isa, Japan

Last updated: July 2, 2025

In Isa, Japan, awareness of the UV Index is crucial for maintaining skin health and preventing sunburn. Understanding UV levels can help residents and visitors make informed choices about sun exposure, especially during peak hours when the risk is highest. With a Cfa climate, Isa experiences significant UV exposure, particularly between 10:00 AM and 2:00 PM when the index can soar to 13—indicating intense ultraviolet radiation. By staying informed about the UV Index, you can take necessary precautions to protect yourself from harmful effects while enjoying the outdoors in this beautiful region.

Hourly UV Index in Isa

The UV Index for the day exhibits a striking daytime peak, rising steadily from a gentle 1 at 07:00 to an intense 13 by 12:00. As the sun reaches its zenith, the 11:00 and 12:00 hours warn of heightened exposure, with the index hitting its maximum at 13:00 before beginning its gradual decline. By 15:00, it slips to 7, reminding us that even in the afternoon, protection is vital. As the day winds down, the UV levels fall back to a safe 1 by 18:00, ensuring a return to safer conditions for evening activities. Stay vigilant and protect your skin during those midday hours!

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	1	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 Isa

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 Isa, Japan

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

The table above highlights how UV exposure in Isa 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.

Isa'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
Isa	5	6	9	11	12	12	12	13	11	8	6	4