UV Index in Joso, Japan

Last updated: June 2, 2025

Awareness of the UV Index in Joso, Japan, is essential for maintaining skin health and preventing sunburn. With the region's Cfa climate, residents and visitors can face significant UV exposure, especially during peak hours. The UV Index reaches a maximum of 11 around midday, indicating a high risk of harm from unprotected sun exposure. Understanding these UV levels empowers you to take proactive measures, ensuring you enjoy the sunny days while keeping your skin safe from the sun’s harmful rays. Stay informed and enjoy the outdoors responsibly!

Hourly UV Index in Joso

The UV Index for the day presents a notable peak at 11:00 AM, where it reaches a striking 11, indicating very high levels of UV radiation. As the sun climbs, the index rises steadily from a moderate 2 at 7:00 AM to a challenging 9 by 10:00 AM. Though it slightly dips to 10 at 12:00 PM, the intensity begins to decline after 1:00 PM, stabilizing around 5 by 3:00 PM, before tapering down to a safe 1 by 5:00 PM. Exposure during the midday hours is critical—taking precautions is essential as the sunlight peaks in intensity!

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	10	very high	15 min
13:00	9	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 Joso

Throughout the year, the UV Index experiences significant seasonal changes, with January and December presenting the lowest levels (UV Index 3) and the summer months of June and July reaching peak levels (UV Index 11), categorized as extreme. April and May also have very high readings (UV Index 9-10), indicating a gradual increase in risk as spring progresses into summer. March, August, and September maintain a high risk for UV exposure (UV Index 7-9). Visitors and residents are advised to take precautions from March through October, especially during the extreme months of June and July, by seeking shade, wearing protective clothing, and applying sunscreen regularly, as burn times decrease significantly to as little as 10 minutes during peak UV periods.

Monthly Maximum UV Index for Joso, Japan

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

The table above highlights how UV exposure in Joso 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.

Joso'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
Joso	3	5	7	9	10	11	11	10	9	7	5	3
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