Weather in Sapporo

On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are July, August, and September. Sapporo is in Japan at 43.1°N. The 2001–2020 NASA POWER daily record describes a continental climate with a wide temperature swing.

August is the warmest month (average 20.2°C, high 24.3°C) and January is the coolest (average -7.0°C, low -9.9°C). Rain is wet season runs from July to January, inside an annual total of 1274 mm. The wettest month is August at 160 mm; the driest is April at 63 mm.

Temperature through the year

Monthly average highs run from -4.1°C in January to 24.3°C in August. Nights follow the same curve: -9.9°C in January and 16.2°C in August.

Mean high across all twelve months is 10.0°C and mean low is 2.4°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

Rainfall pattern

The wet season in Sapporo starts in July and ends in January (July, August, September, October, November, December, and January). August is the core of it at 160 mm. April is the other extreme, with 63 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. August averages 13 such days; April averages 11.

Distinctive months in Sapporo

January closes the wet season: 103 mm over 24 rainy days, then the calendar dries. February: -3.6°C high, -10.3°C low, 84 mm rain, 92% humidity. In March, Sapporo averages 0.0°C by day and -6.5°C at night, with 72 mm of rain. April is the driest month, averaging only 63 mm across 11 rainy days. Highs sit near 7.9°C. May stands apart from the months beside it: 15.2°C / 5.3°C and 74 mm. June: 19.8°C high, 10.4°C low, 82 mm rain, 84% humidity.

July is when the wet season typically starts in Sapporo: highs near 23.4°C, and rainfall jumps to 121 mm (12 rainy days). August is both the hottest and wettest month: highs around 24.3°C, 160 mm of rain, and 86% humidity. September stands apart from the months beside it: 20.3°C / 12.2°C and 137 mm. October stands apart from the months beside it: 13.5°C / 5.4°C and 119 mm. November brings 129 mm and 20 rainy days; temperatures run from -0.9°C to 5.4°C. In December, Sapporo averages -2.0°C by day and -7.3°C at night, with 130 mm of rain.

Best months to visit Sapporo

The three months with the highest comfort score are July, August, and September: July (19.0°C average, 121 mm, 86% humidity); August (20.2°C average, 160 mm, 86% humidity); September (16.2°C average, 137 mm, 85% 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 July–January instead of the score.

How Sapporo compares inside Japan

Saitama is about 809 km away: Sapporo is 5.8°C cooler than Saitama in its hottest month and 175 mm drier over the year than Saitama. Saitama’s wettest month is September (201 mm) versus August here.

Tokyo is about 833 km away: Sapporo is 7.2°C cooler than Tokyo in its hottest month and 420 mm drier over the year than Tokyo. Tokyo’s wettest month is October (246 mm) versus August here.

Yokohama is about 861 km away: Sapporo is 6.0°C cooler than Yokohama in its hottest month and 363 mm drier over the year than Yokohama. Yokohama’s wettest month is October (222 mm) versus August here.