UV Index in Karatsu, Japan

Last updated: May 3, 2025

Understanding the UV Index in Karatsu, Japan is crucial for protecting your skin and overall health. As a popular coastal city with a Cfa climate, Karatsu experiences significant sun exposure, especially during the peak hours when the UV Index reaches levels of 10 and 11. Being aware of these UV levels is essential not just to prevent painful sunburns, but also to safeguard against long-term skin damage. With a climate that encourages outdoor activities, monitoring the UV Index can help you enjoy the sun safely while keeping your skin healthy.

Hourly UV Index in Karatsu

The UV Index throughout the day presents an intriguing pattern of solar intensity. Starting at a mild 1 at 7:00 AM, the index gradually climbs, reaching 3 by 8:00 AM. As the sun rises higher, it peaks at an impressive 11 between 12:00 PM and 1:00 PM, signaling the need for sun protection. As the afternoon wanes, the UV Index dips to 6 at 3:00 PM, before descending further to 4 by 4:00 PM. As evening approaches, the index dwindles to 1 by 6:00 PM, wrapping up a day of fluctuating solar exposure. Be sure to stay safe under the sun during peak 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	1	low	45 min
08:00	3	moderate	30 min
09:00	5	moderate	30 min
10:00	8	very high	15 min
11:00	10	very high	15 min
12:00	11	extreme	10 min
13:00	10	very high	15 min
14:00	8	very high	15 min
15:00	6	high	25 min
16:00	4	moderate	30 min
17:00	2	low	45 min
18:00	1	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Karatsu

The UV Index experiences significant fluctuations throughout the year, with the highest levels occurring from May to September, where it peaks at an extreme level of 12 in both July and August. This period marks the high-risk months for sun exposure, with a critical burn time of just 10 minutes. Conversely, the UV levels are more moderate in January and December, with a UV Index of 4 and a longer burn time of 30 minutes. Residents and visitors are advised to take proactive sun safety measures, particularly during the spring and summer months, including wearing sunscreen, protective clothing, and seeking shade during peak hours when the UV Index is highest.

Monthly Maximum UV Index for Karatsu, Japan

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

The table above highlights how UV exposure in Karatsu 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.

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