UV Index in Tokyo, Japan

Last updated: June 2, 2025

Understanding the UV Index in Tokyo, Japan, is crucial for safeguarding your skin health and preventing sunburn. With the city’s humid subtropical climate (Cfa), Tokyo experiences significant UV exposure, especially during peak hours when the index can reach as high as 11. Knowing the UV levels can help you make informed decisions about sun protection, whether you’re enjoying a sunny day in Ueno Park or commuting across the bustling streets. Stay vigilant and protective; your skin will thank you!

Hourly UV Index in Tokyo

As the day unfolds, the UV Index begins to climb, starting at a mild 2 by 07:00. By 08:00, it ascends to a moderate 5, indicating that sun protection becomes essential. The intensity peaks at 11 between 11:00 and 12:00, marking the hours when solar radiation is most potent. Following this peak, the index gradually declines; it drops to 10 at 13:00, before descending to 7 by 14:00. The afternoon sees a further decrease, with readings of 5 at 15:00 and 3 at 16:00—perfect for those wishing to enjoy the sun while still being cautious. By 17:00, the index falls to a mild 1, and as the day winds down, it reaches 0 by 19:00, signaling a retreat from the sun's harmful rays. It’s crucial to stay informed and protect your skin during peak UV 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	5	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	3	moderate	30 min
17:00	1	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Tokyo

As the seasons change, the UV Index fluctuates significantly, influencing the risk of sun exposure throughout the year. January and February start with a moderate UV Index of 3 and 5, allowing for a burn time of 30 minutes. However, by March, the UV Index jumps to 8, which is categorized as very high, reducing safe exposure to just 15 minutes. The peak months for UV radiation are May through August, where the Index reaches an extreme level of 11, necessitating a mere 10 minutes of exposure before risking sunburn. September begins a gradual decline to a very high index of 10, while October and onward return to moderate levels. Visitors and residents should be particularly cautious from March to August—wearing protective clothing, applying sunscreen, and seeking shade to minimize UV damage during these high-risk months.

Monthly Maximum UV Index for Tokyo, Japan

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

The table above highlights how UV exposure in Tokyo 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.

Tokyo'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
Tokyo	3	5	8	9	11	11	11	11	10	7	5	4
Yokohama 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