UV Index in Hakone, Japan

Last updated: August 1, 2025

Understanding the UV Index in Hakone, Japan, is crucial for protecting your skin and overall health, especially during the sunny months. The UV levels here can vary significantly throughout the day, peaking at a high of 12 between noon and 1 PM, which is classified as a "very high" risk for harm from unprotected sun exposure. Being aware of these UV levels helps residents and visitors alike take essential precautions against sunburn and long-term skin damage. Hakone, with its Cfa climate, offers stunning landscapes but also presents challenges with UV exposure, particularly during peak hours when the sun's rays can be most intense. Make sure to stay informed and stay safe under the sun!

Hourly UV Index in Hakone

The UV index today begins with a gentle rise, starting at a modest 2 at 7:00 AM. As the sun climbs higher, it reaches 5 by 8:00 AM, quickly escalating to a peak 12 by both 11:00 AM and 12:00 PM—indicating the highest intensity of UV radiation. From that point, the index starts to decline, dropping to 11 at 1:00 PM, and then gently easing down to 8 by 2:00 PM. The afternoon watches the UV levels further retreat to 6 at 3:00 PM, finally tapering off to a cool 1 by 5:00 PM, settling to 0 by 7:00 PM. It's a day where early sun seekers must take care, especially during the midday 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	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 Hakone

Throughout the year, the UV Index demonstrates notable seasonal changes, with the most intense exposure occurring from April to August. During these months, the UV Index reaches extreme levels (10-12), significantly reducing the burn time to just 10 minutes. March and September also pose risks with very high levels (8-10), allowing for a burn time of only 15 minutes. Consequently, February and October present high levels (6-7), where protective measures are still advised with adjusted burn times of 25 minutes. Residents and visitors should exercise caution and protect their skin, especially during the high-risk months of April through August, by using sunscreen, wearing protective clothing, and limiting sun exposure during peak hours.

Monthly Maximum UV Index for Hakone, Japan

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

The table above highlights how UV exposure in Hakone 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.

Hakone'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
Hakone	4	6	8	10	11	11	12	11	10	7	5	4
Osaka UVI	4	6	8	11	11	11	12	11	10	7	5	3