UV Index in Niihama, Japan

Last updated: May 3, 2025

In Niihama, Japan, awareness of the UV Index is crucial for residents and visitors alike, as it serves as a vital indicator of sun exposure risk. Understanding UV levels is essential not only for preventing painful sunburn but also for protecting long-term skin health against damaging rays. With Niihama's Cfa climate, known for its distinct seasons, sun exposure can vary significantly, especially during peak hours when UV Index readings soar to as high as 11 from 11:00 AM to 1:00 PM. Staying informed about these levels enables you to enjoy the beautiful outdoors safely while safeguarding your skin.

Hourly UV Index in Niihama

As the sun rises, the UV Index gradually climbs, starting at a modest 2 by 07:00 and reaching its peak of 11 between 11:00 and 13:00. This is the time when sun protection is most crucial, as the intensity of UV radiation can lead to skin damage in just a short period. After the midday zenith, the index begins to decline, dropping to 8 by 14:00, and easing further to 3 by 16:00. As daylight wanes, the UV Index decreases significantly, plummeting to 0 by 19:00. It's important to remain vigilant during the peak hours to safeguard your skin while enjoying the outdoors!

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	3	moderate	30 min
09:00	6	high	25 min
10:00	9	very high	15 min
11:00	11	extreme	10 min
12:00	11	extreme	10 min
13:00	11	extreme	10 min
14:00	8	very high	15 min
15:00	6	high	25 min
16:00	3	moderate	30 min
17:00	2	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Niihama

Throughout the year, UV radiation levels dramatically fluctuate, impacting the risk of skin damage for both visitors and residents. The highest risk months occur from May to August, where the UV Index peaks at 11 to 12, indicating an extreme exposure category with a burn time of just 10 minutes. During these months, it is crucial to limit direct sun exposure and utilize protective measures such as sunscreen, hats, and clothing to safeguard skin health. March and April also present high levels of concern, categorized as very high with burn times of just 15 minutes. As seasons shift into fall and winter, the UV Index decreases, with December and January showing a moderate level, allowing for longer safe exposure times of 30 minutes. However, even during lower UV months, protective precautions are still advised. Stay informed and protect yourself year-round!

Monthly Maximum UV Index for Niihama, Japan

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

The table above highlights how UV exposure in Niihama 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.

Niihama'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
Niihama	4	6	8	10	11	11	12	12	10	7	6	4