UV Index in Ajigasawa, Japan

Last updated: June 2, 2025

In Ajigasawa, Japan, awareness of the UV Index is crucial for protecting your skin from harmful ultraviolet radiation. Understanding UV levels is essential in preventing sunburn and promoting long-term skin health, especially during the peak hours when the index reaches a maximum of 10 around noon. Nestled in a Cfa climate zone, Ajigasawa enjoys a temperate climate but presents notable UV exposure risks, particularly between 10 AM and 2 PM. Staying informed about UV levels ensures you can enjoy the outdoors while minimizing your risk of sun-related damage.

Hourly UV Index in Ajigasawa

During the day, the UV Index experiences a dynamic shift, peaking in the late morning. Starting at 3 at 07:00, it escalates to reach a high of 10 by 11:00 and remains there until 12:00. As afternoon approaches, the index gradually declines, dropping back to 9 by 13:00, then to 7 at 14:00. By the mid to late afternoon, it continues its descent, falling to 5 at 15:00 and further down to 3 by 16:00. In the evening, the index diminishes significantly, plummeting to 1 at both 17:00 and 18:00, and finally reaching 0 by 19:00. This pattern highlights the importance of sun protection during the peak hours of 10:00 to 12:00 when the UV radiation is most intense.

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	9	very high	15 min
14:00	7	high	25 min
15:00	5	moderate	30 min
16:00	3	moderate	30 min
17:00	1	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Ajigasawa

Throughout the year, UV levels fluctuate significantly, with higher levels observed from March to September. The peak risk months are June, July, and August, where the UV Index reaches as high as 11, categorized as extreme, boasting a burn time of just 10 minutes. In spring, particularly April and May, the UV exposure escalates to very high levels (Index of 8-9), requiring heightened awareness. From October to March, UV Index values decrease, though residents and visitors should still take precautions in March (Index of 6) and October (Index of 6) due to higher risk levels. As a general guideline, it’s advisable to wear sunscreen and protective clothing, especially during peak hours, from March to August, to minimize sun exposure and reduce the risk of skin damage.

Monthly Maximum UV Index for Ajigasawa, Japan

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

The table above highlights how UV exposure in Ajigasawa 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.

Ajigasawa'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
Ajigasawa	3	4	6	8	9	10	10	11	8	6	4	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