UV Index in Osaka, Japan

Last updated: July 2, 2025

In Osaka, Japan, understanding the UV Index is crucial for safeguarding your skin and overall health. With the city's Cfa climate, which brings hot summers and mild winters, UV levels can become quite intense, especially from late spring through early fall. By staying informed about daily UV indices, you can effectively prevent sunburn and reduce long-term skin damage. For instance, during peak hours, such as between 10:00 AM and 1:00 PM, the UV Index can soar to levels exceeding 11, indicating a high risk of harm from unprotected sun exposure. Being aware of these fluctuations empowers you to enjoy the sun safely while staying proactive about your skin health!

Hourly UV Index in Osaka

The UV Index throughout the day exhibits a dramatic rise, peaking at 12 around noon. Starting from a humble 2 at 7:00 AM, the intensity steadily climbs as the sun ascends. By 10:00 AM, it reaches 9, signaling that sun protection is essential. The zenith occurs at 11:00 AM with a staggering 11, followed closely by 12 at noon, making it crucial to seek shade and wear sunscreen. The index begins to taper off in the afternoon, descending to 6 by 3:00 PM, and then falls further to 1 as evening sets in. This trend underscores the importance of monitoring UV levels to ensure safe sun exposure at its peak.

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	4	moderate	30 min
09:00	7	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	6	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 Osaka

Throughout the year, UV exposure varies significantly, with the highest levels observed from March to August, peaking at a UV Index of 12 in July. This period includes extreme levels of risk, where the recommended burn time is as little as 10 minutes. Visitors and residents should exercise caution during these months, particularly in April, May, June, and July, by seeking shade, wearing protective clothing, and using sunscreen. Conversely, January, November, and December present lower risk categories, with moderate exposure and longer burn times of 30 minutes. To ensure safety, it’s crucial to stay informed about the UV Index and adjust outdoor activities accordingly throughout the year.

Monthly Maximum UV Index for Osaka, Japan

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

The table above highlights how UV exposure in Osaka 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.

Osaka'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	4	6	8	11	11	11	12	11	10	7	5	3