What is the UV index in Yokohama today?

See today's UV index for Yokohama hour by hour above. The UV index is highest around solar noon and depends on the season, the weather and how high the sun rises above the horizon.

When is the UV index highest?

The UV index peaks around solar noon, typically between 12:00 and 15:00, when the sun is highest in the sky. About two-thirds of the day’s total UV falls between 10:00 and 16:00.

When should you use sunscreen?

The WHO recommends sun protection whenever the UV index is 3 or higher. Use sunscreen of at least SPF 30, seek shade around midday, and wear sunglasses and a hat when UV is high.

Daylight Hours › UV Index › Yokohama

UV Index in Yokohama Today

October 19, 2026 · Yokohama, Japan

3,574,443 people

See today's UV index in Yokohama hour by hour below. The UV index shows how strong the sun's ultraviolet radiation is — the higher the number, the faster skin can burn. Values are calculated for Yokohama's coordinates and updated daily.

UV now · 08:00

2Low

UV rises later today

Peak today5at 11:00

Protect yourself09:00–13:19UV 3 or above

Time to burn~35 minfair skin, unprotected

Hour by hour

Protection windowClear sky

Remember today

Sunscreen SPF 30+
Sunglasses

Daylight: sunrise 05:51 – sunset 17:03

Tomorrow: UV 3 at its peak around 12:00

Calculate for Yokohama Use my location

The UV index in Yokohama peaks at 5 (moderate) around 11:00 today. Sun protection is recommended between 09:00 and 13:19, while the index stays at 3 or above. Tomorrow the index is forecast to peak at 3 around 12:00.

UV index in Yokohama hour by hour

Time	UV index	Level
05:00	0	Low
06:00	0.1	Low
07:00	0.5	Low
08:00	1.5	Low
09:00	3	Moderate
10:00	4.1	Moderate
11:00	4.9	Moderate
12:00	4.9	Moderate
13:00	3.6	Moderate
14:00	1.7	Low
15:00	0.5	Low
16:00	0.1	Low
17:00	0	Low
18:00	0	Low

UV index in Yokohama

Yokohama lies at 35°N. The midday sun reaches 44.8° above the horizon in Yokohama today, against a yearly ceiling of 78.0°. Elevation is what sets the ceiling for UV, and over Yokohama it is high enough for the index to reach very high values through the summer months.

What is the UV index?

The UV index is an international scale describing the strength of the sun's ultraviolet radiation at ground level. It starts at 0 and is effectively open-ended — at mid-latitudes it rarely exceeds 8, while in the tropics and high in the mountains it can pass 11. The higher the number, the less time it takes to get sunburnt.

The UV index depends mainly on how high the sun is in the sky. That is why it peaks around solar noon and is greatest in summer near the longest day of the year. Clouds, ozone, altitude and reflection from snow or water also affect the value.

The WHO UV scale

UV index	Level	Recommendation
0–2	Low	No special protection needed.
3–5	Moderate	Use sunscreen (SPF 30+), seek shade around midday.
6–7	High	Sunscreen, hat and sunglasses. Avoid the sun 12:00–15:00.
8–10	Very high	Extra protection. Limit midday sun exposure.
11+	Extreme	Avoid the sun at midday. Full protection required.

See also sunrise, sunset and daylight hours in Yokohama.