UV Index in Aka, Japan

Last updated: July 2, 2025

Awareness of the UV Index is crucial for residents and visitors in Aka, Japan, where the Cfa climate contributes to varying UV exposure levels throughout the day. Understanding these levels is essential not only for preventing sunburn but also for protecting long-term skin health. In Aka, UV radiation peaks dramatically during midday hours, reaching a maximum of 12 around noon, highlighting the need for vigilance against potential skin damage during the warmer seasons. By staying informed about the UV Index, you can enjoy the beautiful, sunny days in Aka while safeguarding your skin from harmful effects.

Hourly UV Index in Aka

The UV Index for the day reveals a dynamic shift in sun exposure, peaking dramatically between 11:00 AM and 1:00 PM. Starting the morning with a mild maximum of 2 at 7:00 AM, the index steadily rises, reaching 12 by midday—an indication of high risk for harm from unprotected sun exposure. As the afternoon progresses, it dips to 10 at 2:00 PM and then gradually decreases to a more moderate level of 4 by 4:00 PM. By the evening, the UV Index settles back down to 1 by 6:00 PM, signaling a safe time to enjoy the outdoors again. Be sure to protect your skin during those peak 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	2	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	12	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 Aka

Throughout the year, seasonal changes in UV exposure highlight periods of heightened risk for residents and visitors. From January to February, the UV Index rises from 4 (moderate) to 6 (high), reducing safe exposure time to 25 minutes. Significant increases occur in March, reaching 8 (very high), and peaking during the summer months of April to August at 11-12 (extreme), where only 10 minutes of unprotected exposure is advisable. The risk, while still present, decreases again in September and returns to high levels in October and November with a UV Index of 6-7, allowing for 25 minutes of safe exposure. As such, it is crucial for visitors and residents to remain vigilant, especially during the summer, taking precautions like wearing sunscreen, protective clothing, and seeking shade during peak hours to mitigate the risk of UV-related health issues.

Monthly Maximum UV Index for Aka, Japan

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

The table above highlights how UV exposure in Aka 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.

Aka'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
Aka	4	6	8	11	11	11	12	12	11	7	6	4