UV Index in Ogasawara, Japan

Last updated: May 3, 2025

In the picturesque Ogasawara Islands, understanding the UV Index is crucial for residents and visitors alike to safeguard their skin health. With UV levels soaring as high as 12 during the midday sun, awareness of these risks is essential for preventing sunburn and long-term skin damage. The region's Cfa climate brings significant sunlight throughout the year, making it vital to monitor UV exposure. By staying informed about the UV Index, you can enjoy the stunning natural beauty of Ogasawara while protecting your skin from harmful rays.

Hourly UV Index in Ogasawara

The UV Index throughout the day presents a clear picture of sun intensity, peaking impressively at 12 between 11:00 AM and 12:00 PM. Starting from a mild 3 at 7:00 AM, the index climbs steadily to reach a striking 11 by 10:00 AM, indicating a strong need for sun protection. As the sun is at its highest, the UVI holds steady, emphasizing the importance of staying in the shade or wearing sunscreen during these hours. By 1:00 PM, it begins to taper off, dropping to 10 before significantly declining to 4 by 3:00 PM and then dipping further through the evening. The day concludes with a low 0 at 7:00 PM, signifying that after a powerful midday sun, the UV exposure becomes negligible as the day winds down.

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	8	very high	15 min
10:00	11	extreme	10 min
11:00	12	extreme	10 min
12:00	12	extreme	10 min
13:00	10	very high	15 min
14:00	7	high	25 min
15:00	4	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 Ogasawara

Throughout the year, UV exposure varies significantly, peaking during the spring and summer months. Notably, March through September experience extreme UV levels, with indices consistently reaching 12 or higher, indicating a high risk for sunburn. In particular, April to July holds the highest UV ratings, making these months crucial for sun protection. High-risk months include February to October, with a sharp increase from February's very high index of 9 to April's extreme index of 13. Residents and visitors should be particularly vigilant in these months, limiting sun exposure between 10 AM and 4 PM and utilizing sunscreen, protective clothing, and sunglasses to mitigate UV damage effectively. As UV levels decrease in November and December, while still cautioning against exposure, the risk diminishes significantly.

Monthly Maximum UV Index for Ogasawara, Japan

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

The table above highlights how UV exposure in Ogasawara 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.

Ogasawara'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
Ogasawara	7	9	11	13	12	13	13	12	12	10	8	6