UV Index in Niiza, Japan

Last updated: May 3, 2025

In Niiza, Japan, being aware of the UV Index is crucial for safeguarding your skin from harmful solar radiation. Understanding UV levels is essential not just for preventing sunburn but also for maintaining long-term skin health. With a Cfa climate that features warm summers, the risk of exposure can be significant, especially during midday hours when UV levels peak at a striking 11. By staying informed about daily UV trends, residents and visitors alike can enjoy the sun safely while minimizing the risk of skin damage and related health issues.

Hourly UV Index in Niiza

As the sun rises, the UV Index begins its ascent, reaching a gentle 2 by 07:00. By 08:00, it climbs to a moderate 5, signaling the start of a day to be mindful of sun exposure. The intensity peaks at 11 from 11:00 to 12:00, marking the golden hours when protective measures are crucial. As the afternoon unfolds, the value dips to 9 at 13:00 and continues its descent to 7 by 14:00. By the late afternoon, the UV Index relaxes significantly, falling to 4 at 15:00 and tapering off to 2 by 16:00. As the sun sets, it becomes a safe 1 at 17:00, finally reaching a calm 0 after 19:00. This data highlights the importance of sun safety practices during peak hours, especially between 10:00 and 14:00.

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	9	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 Niiza

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 Niiza, Japan

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

The table above highlights how UV exposure in Niiza 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.

Niiza'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
Niiza	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
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