UV Index in Naganohara, Japan

Last updated: August 1, 2025

Awareness of the UV Index is crucial for residents and visitors of Naganohara, Japan, as it directly impacts skin health and sunburn prevention. Understanding UV levels is essential, particularly in this Dfb climate zone, where typical exposure risks can peak during the summer months. With UV Index values reaching 11 around noon, it's vital to take precautions to safeguard your skin. Stay informed to enjoy Naganohara's beautiful outdoors while minimizing the risks associated with harmful ultraviolet radiation.

Hourly UV Index in Naganohara

The UV Index throughout the day presents a dynamic picture of sun exposure. As early as 7:00 AM, the index starts at a mild 2, ramping up to a moderate 4 by 8:00 AM. The sun's intensity peaks around 11:00 AM and 12:00 PM with a striking 11, marking the height of caution for outdoor activities. As we move into the afternoon, the index gradually declines, dropping to 8 by 2:00 PM and further to 5 by 3:00 PM. The evening brings relief, with the UV Index decreasing to a 1 by 5:00 PM and finally hitting 0 by 7:00 PM. It’s clear that the midday hours pose the greatest risk, so sun safety measures are essential during those peak times.

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	8	very high	15 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 Naganohara

Throughout the year, UV exposure varies significantly, with the highest risk months being May through August when the UV Index reaches an extreme level of 11. During these months, the recommended burn time is reduced to just 10 minutes, necessitating vigilant sun protection practices. Notably, March and April also present high risk, characterized by very high UV indices of 8 and 9, respectively, with burn times of just 15 minutes. As UV levels taper off from September to December, residents and visitors should remain cautious, especially in the early months of spring. It’s vital for everyone to stay informed about UV levels and take appropriate protective measures, such as applying sunscreen, wearing protective clothing, and seeking shade, particularly during peak hours.

Monthly Maximum UV Index for Naganohara, Japan

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

The table above highlights how UV exposure in Naganohara 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.

Naganohara'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
Naganohara	4	6	8	9	11	11	11	11	10	7	5	3
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