UV Index in Oshima, Japan

Last updated: May 3, 2025

Understanding the UV Index in Oshima, Japan, is crucial for safeguarding your skin and overall health. With UV levels regularly peaking during the sunny hours, knowing the index can help you prevent sunburn and reduce long-term skin damage. Oshima's Cfa climate often brings bright, clear skies, which can elevate UV exposure risks significantly, especially around midday when values may soar to 11. Being aware of these fluctuations not only enhances your sun safety but also allows you to enjoy the island's beautiful outdoors responsibly.

Hourly UV Index in Oshima

At dawn, the UV Index (UVI) starts gently at a modest 2 by 07:00. As the sun rises, it climbs steadily, reaching a lively 4 by 08:00. The intensity peaks dramatically at 11:00 and 12:00, both hitting a robust 11, indicating a high risk for sun exposure. The afternoon brings a gradual decline; by 14:00, the UVI dips to 7, and continues to fall to 5 by 15:00. As the sun sets, the UVI returns to safer levels, hitting 2 at 16:00 and decreasing further to a mere 0 by 19:00, signaling a day well spent under the sun with precautions taken during the 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	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	11	extreme	10 min
13:00	10	very high	15 min
14:00	7	high	25 min
15:00	5	moderate	30 min
16:00	2	low	45 min
17:00	1	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Oshima

The UV Index experiences significant seasonal variation, with March through September being the high-risk months for sun exposure. March begins the rise with an index of 8 (very high) and only a 15-minute burn time, peaking in July with an index of 12 (extreme) and a mere 10-minute burn time. May through August consistently holds an extreme exposure category, urging increased caution during these months. As summer transitions into fall, the index gradually decreases, with October dropping to 7 (high) and 15-minute burn times for October and September, before returning to moderate levels in winter. Visitors and residents are advised to take precautions during the high-risk months by seeking shade, wearing protective clothing, and applying sunscreen regularly to minimize the risk of skin damage.

Monthly Maximum UV Index for Oshima, Japan

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

The table above highlights how UV exposure in Oshima 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.

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