Sendai, Japan climate

Cfa Humid subtropical

Sendai has a seasonal mild-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is August with an average daily high near 28°C, while the coldest is January averaging around −1°C at night. Precipitation totals about 1277 mm a year and is strongly seasonal — September alone averages 193 mm while February barely receives 34 mm.

☀️ Summers

Warm

Highs near 28°C in August.

❄️ Winters

Cold

Lows near −1°C in January.

🌧️ Rain

Wet

About 1277 mm of rain a year.

Wettest in September

⛅ Sky & trend

Often grey

Overcast skies dominate much of the year.

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Hours of sunshine per day

Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)

Sendai climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	6	7	10	16	20	23	27	28	25	20	14	8
Avg temp (°C)	2	2	6	11	16	19	23	24	21	16	10	5
Avg low (°C)	−1	−1	1	6	12	16	20	22	18	12	6	1
Precipitation (mm)	42	34	74	90	110	144	178	158	193	151	59	44

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	6	7	10	16	20	23
Avg temp (°C)	2	2	6	11	16	19
Avg low (°C)	−1	−1	1	6	12	16
Precipitation (mm)	42	34	74	90	110	144

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	27	28	25	20	14	8
Avg temp (°C)	23	24	21	16	10	5
Avg low (°C)	20	22	18	12	6	1
Precipitation (mm)	178	158	193	151	59	44

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	77	75	73	71	71	77	80	71	76	72	74	79
Relative humidity (%)	95	93	87	82	81	83	86	85	87	87	89	93
Wind speed (m/s)	1.9	2.2	2.0	1.4	0.9	0.7	0.7	0.7	0.7	0.8	0.9	1.3

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	77	75	73	71	71	77
Relative humidity (%)	95	93	87	82	81	83
Wind speed (m/s)	1.9	2.2	2.0	1.4	0.9	0.7

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	80	71	76	72	74	79
Relative humidity (%)	86	85	87	87	89	93
Wind speed (m/s)	0.7	0.7	0.7	0.8	0.9	1.3

Methodology & sources

Temperature & precipitation — the official 1991–2020 climate normals from the Japan Meteorological Agency, measured at Sendai, about 3 km from the city centre.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →