Okayama, Japan climate

Cfa Humid subtropical

Okayama has a seasonal mild-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is August with an average daily high near 33°C, while the coldest is January averaging around 0°C at night. Precipitation totals about 1143 mm a year and is strongly seasonal — July alone averages 177 mm while January barely receives 36 mm.

☀️ Summers

Hot

Highs near 33°C in August.

❄️ Winters

Chilly

Lows near 0°C in January.

🌧️ Rain

Wet

About 1143 mm of rain a year.

Wettest in July

⛅ Sky & trend

Often cloudy

Cloudy skies 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)

Okayama climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	10	11	15	20	25	28	32	33	29	23	17	12
Avg temp (°C)	5	5	9	14	19	23	27	28	24	18	12	7
Avg low (°C)	0	1	4	9	15	19	23	25	20	13	7	2
Precipitation (mm)	36	45	82	90	113	169	177	97	142	95	53	42

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	10	11	15	20	25	28
Avg temp (°C)	5	5	9	14	19	23
Avg low (°C)	0	1	4	9	15	19
Precipitation (mm)	36	45	82	90	113	169

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	32	33	29	23	17	12
Avg temp (°C)	27	28	24	18	12	7
Avg low (°C)	23	25	20	13	7	2
Precipitation (mm)	177	97	142	95	53	42

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	77	74	70	66	69	79	73	66	72	67	69	74
Relative humidity (%)	78	77	76	76	77	81	83	80	80	79	79	79
Wind speed (m/s)	3.3	3.2	3.1	2.7	2.3	2.0	2.1	2.1	2.5	2.6	2.6	3.1

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	77	74	70	66	69	79
Relative humidity (%)	78	77	76	76	77	81
Wind speed (m/s)	3.3	3.2	3.1	2.7	2.3	2.0

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	73	66	72	67	69	74
Relative humidity (%)	83	80	80	79	79	79
Wind speed (m/s)	2.1	2.1	2.5	2.6	2.6	3.1

Methodology & sources

Temperature & precipitation — the official 1991–2020 climate normals from the Japan Meteorological Agency, measured at Okayama, about 4 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 →