UV Index in Aya, Japan

Last updated: June 2, 2025

In Aya, Japan, being aware of the UV Index is crucial for protecting your skin and overall health. The UV Index measures the strength of ultraviolet radiation from the sun, with higher levels indicating an increased risk of sunburn, skin damage, and long-term health issues. With Aya's humid subtropical climate, residents and visitors alike face significant UV exposure, especially during midday hours when values can soar to a dangerous 12. Understanding these levels can help you make informed decisions about sun protection, ensuring you enjoy the beautiful outdoors safely while minimizing the risks associated with excessive sun exposure.

Hourly UV Index in Aya

The UV Index throughout the day showcases a dynamic shift in sun intensity, peaking at 12 around noon. Beginning with a gentle 2 at 7:00 AM, the index steadily increases, hitting 11 by 11:00 AM as the sun climbs higher. By 12:00 PM, the sun reaches its zenith at 12, marking the highest UV exposure, making sun safety a priority. As the afternoon progresses, from 1:00 PM to 3:00 PM, the UV Index gradually decreases to 9 by 2:00 PM and 7 by 3:00 PM. The day winds down with a notable drop in intensity, returning to a mild 1 by 6:00 PM, emphasizing that the safest time to enjoy the sun is before noon or after 4:00 PM.

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	11	extreme	10 min
14:00	9	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 Aya

Throughout the year, UV levels exhibit significant seasonal variations, with the highest risk emerging during the spring and summer months. From March to September, the UV Index reaches very high to extreme levels, with peak values of 13 in July and August, indicating a burn time of just 10 minutes. This period represents the highest risk for sunburn; hence, it’s crucial for residents and visitors to take protective measures such as wearing sunscreen, protective clothing, and hats. Meanwhile, January and December present moderate UV exposure, while November and February fall into the high category, necessitating some caution. Overall, it is advisable to remain vigilant during March to September, especially around midday when the sun's rays are strongest.

Monthly Maximum UV Index for Aya, Japan

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

The table above highlights how UV exposure in Aya 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.

Aya'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
Aya	5	6	10	10	12	12	13	13	11	8	6	4