Weather in Yokohama

Rain is wet season runs from March to November, inside an annual total of 1636 mm. The wettest month is October at 222 mm; the driest is January at 66 mm.

Yokohama is in Japan at 35.4°N. The 2001–2020 NASA POWER daily record describes a continental climate with a wide temperature swing. August is the warmest month (average 26.2°C, high 30.3°C) and January is the coolest (average 2.9°C, low -1.8°C). On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are June, July, and September.

Temperature through the year

The heat peaks in August, when the typical afternoon is 30.3°C. The opposite pole is January, when mornings average -1.8°C.

Mean high across all twelve months is 18.8°C and mean low is 9.6°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

Rain through the year

The wet season in Yokohama starts in March and ends in November (March, April, May, June, July, August, September, October, and November). October is the core of it at 222 mm. January is the other extreme, with 66 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. October averages 12 such days; January averages 5.

Distinctive months in Yokohama

January is the coolest month, with lows around -1.8°C and highs near 7.5°C. Rainfall is 66 mm. March is when the wet season typically starts in Yokohama: highs near 12.5°C, and rainfall jumps to 115 mm (10 rainy days). April: 17.5°C high, 6.6°C low, 129 mm rain, 78% humidity. In May, Yokohama averages 22.2°C by day and 12.1°C at night, with 142 mm of rain. June brings 181 mm and 15 rainy days; temperatures run from 16.9°C to 25.2°C. July stands apart from the months beside it: 28.9°C / 21.1°C and 180 mm.

Peak heat arrives in August: 30.3°C by day, 22.2°C at night, and 82% humidity. In September, Yokohama averages 26.4°C by day and 18.4°C at night, with 215 mm of rain. October is the wettest month — 222 mm and 12 rainy days, with 84% humidity. By November the wet season is ending. Yokohama still sees about 97 mm, but the next month is usually leaner. December stands apart from the months beside it: 10.3°C / 0.6°C and 69 mm.

Best months to visit Yokohama

The three months with the highest comfort score are June, July, and September: June (21.0°C average, 181 mm, 83% humidity); July (25.0°C average, 180 mm, 84% humidity); September (22.4°C average, 215 mm, 84% humidity). They fall in calendar order. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you want the wet season itself — fewer crowds, greener landscape, heavier rain — aim at March–November instead of the score.

How Yokohama compares inside Japan

Tokyo is about 29 km away: Yokohama is 1.2°C cooler than Tokyo in its hottest month and 57 mm drier over the year than Tokyo. Tokyo’s wettest month is October (246 mm) versus October here.

Saitama is about 53 km away: Yokohama is about as warm as Saitama at the hot peak and 187 mm wetter over the year than Saitama. Saitama’s wettest month is September (201 mm) versus October here.

Nagoya is about 251 km away: Yokohama is 1.1°C cooler than Nagoya in its hottest month and 105 mm drier over the year than Nagoya. Nagoya’s wettest month is July (225 mm) versus October here.