Weather in Tokyo

Rain is wet season runs from March to November, inside an annual total of 1693 mm. The wettest month is October at 246 mm; the driest is February at 75 mm.

Tokyo is in Japan at 35.7°N. The 2001–2020 NASA POWER daily record describes a humid subtropical climate. August is the warmest month (average 27.4°C, high 31.1°C) and January is the coolest (average 5.0°C, low 0.9°C). On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are May, June, and September.

When Tokyo gets wet

The wet season in Tokyo starts in March and ends in November (March, April, May, June, July, August, September, October, and November). October is the core of it at 246 mm. February is the other extreme, with 75 mm.

Humidity peaks near 83%. That usually lines up with the wetter months rather than the hottest ones.

Hot and cool months in Tokyo

Monthly average highs run from 9.0°C in January to 31.1°C in August. Nights follow the same curve: 0.9°C in January and 23.7°C in August.

Across the year the mean afternoon high is 19.8°C. If you want the smallest day–night shock, look at months where the high and low sit close together; August nights still hold 23.7°C.

The calendar in Tokyo

The year bottoms out in January. Plan for 0.9°C at night and 9.0°C in the afternoon. February is the driest month, averaging only 75 mm across 8 rainy days. Highs sit near 10.1°C. The wet season opens in March. Expect 124 mm and 11 rainy days, with nights around 4.1°C. In April, Tokyo averages 18.2°C by day and 8.8°C at night, with 135 mm of rain. May: 22.8°C high, 14.0°C low, 148 mm rain, 79% humidity. June stands apart from the months beside it: 25.8°C / 18.3°C and 185 mm.

July brings 152 mm and 15 rainy days; temperatures run from 22.4°C to 29.5°C. August is the warmest month. Afternoon highs average 31.1°C and nights settle near 23.7°C, with 134 mm of rain. September: 27.6°C high, 20.5°C low, 211 mm rain, 82% humidity. October is the wettest month — 246 mm and 14 rainy days, with 82% humidity. November closes the wet season: 120 mm over 10 rainy days, then the calendar dries. December: 11.6°C high, 3.5°C low, 83 mm rain, 78% humidity.

When the score favours a visit

The three months with the highest comfort score are May, June, and September: May (18.4°C average, 148 mm, 79% humidity); June (22.1°C average, 185 mm, 82% humidity); September (24.0°C average, 211 mm, 82% 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.

Tokyo and other cities in Japan

Saitama is about 25 km away: Tokyo is 1.4°C warmer than Saitama in its hottest month and 245 mm wetter over the year than Saitama. Saitama’s wettest month is September (201 mm) versus October here.

Yokohama is about 29 km away: Tokyo is 1.2°C warmer than Yokohama in its hottest month and 57 mm wetter over the year than Yokohama. Yokohama’s wettest month is October (222 mm) versus October here.

Nagoya is about 259 km away: Tokyo is about as warm as Nagoya at the hot peak and 48 mm drier over the year than Nagoya. Nagoya’s wettest month is July (225 mm) versus October here.