Weather and climate in Tokyo, Japan: monthly averages and best time for stargazing

Best for stargazingDec, Jan, NovMost clear, dark hours

Warmest monthAugustAverage high 31°C

Coolest monthJanuaryAverage low 1°C

Wettest monthOctober246 mm on average

What the weather is like in Tokyo

The warmest month in Tokyo is August, with average highs of 31°C. The coolest is January, when nights average 1°C. About 1,693 mm of rain and snow falls in a typical year, most in October and least in February.

Skies are clearest in August (61% average cloud cover) and cloudiest in June (81%). Combining cloud with the length of truly dark nights, December, January, November offer the most clear, dark hours for stargazing.

Clear, dark hours per night

3.7 Jan

2.9 Feb

2.7 Mar

2.4 Apr

1.8 May

1.1 Jun

1.6 Jul

2.9 Aug

2.6 Sep

2.6 Oct

3.1 Nov

3.8 Dec

Hours of full astronomical darkness in mid-month, multiplied by the average share of clear sky. A rough guide to how much good observing time a typical night offers.

Monthly averages

Month	High	Low	Precipitation	Cloud cover	Humidity	Wind	Dark hours
January	9°C	1°C	80 mm	66%	75%	10 km/h	11.0 h
February	10°C	1°C	74 mm	72%	76%	10 km/h	10.2 h
March	13°C	4°C	124 mm	71%	76%	11 km/h	9.2 h
April	18°C	9°C	135 mm	70%	77%	11 km/h	7.9 h
May	23°C	14°C	148 mm	72%	79%	10 km/h	6.6 h
June	26°C	18°C	185 mm	81%	82%	8 km/h	5.8 h
July	29°C	22°C	153 mm	75%	83%	9 km/h	6.2 h
August	31°C	23°C	134 mm	61%	81%	8 km/h	7.4 h
September	27°C	20°C	211 mm	71%	82%	9 km/h	8.7 h
October	22°C	14°C	246 mm	73%	82%	9 km/h	9.9 h
November	17°C	9°C	120 mm	71%	80%	8 km/h	10.8 h
December	11°C	3°C	83 mm	66%	78%	9 km/h	11.2 h

Climate averages: NASA POWER, 2001–2025, for the grid area around 35.50, 140.00 (about 50 km across). High and low temperatures are estimated from the monthly mean and the average daily range. Hills, coasts and cities can differ from the area average. Sources and methods.