Surabaya, Indonesia climate

Aw Tropical savanna (dry winter)

Surabaya has a remarkably steady tropical climate (Tropical savanna (dry winter), Köppen Aw). The hottest month is October with an average daily high near 35°C, while the coldest is July averaging around 24°C at night. Precipitation totals about 999 mm a year and is strongly seasonal — January alone averages 195 mm while August barely receives 3 mm.

☀️ All year

Hot

Daytime highs near 35°C most of the year.

🌙 Nights

Stays warm

Even the coolest nights stay near 24°C.

🌧️ Rain

Moderate rainfall

About 999 mm of rain a year.

Wettest in January

⛅ 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)

Surabaya climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	32	32	33	33	33	33	32	33	34	35	34	33
Avg temp (°C)	28	28	29	29	29	29	28	28	29	30	30	29
Avg low (°C)	25	25	25	25	25	24	24	23	24	25	26	25
Precipitation (mm)	195	180	190	76	38	30	15	3	8	29	70	164

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	32	32	33	33	33	33
Avg temp (°C)	28	28	29	29	29	29
Avg low (°C)	25	25	25	25	25	24
Precipitation (mm)	195	180	190	76	38	30

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	32	33	34	35	34	33
Avg temp (°C)	28	28	29	30	30	29
Avg low (°C)	24	23	24	25	26	25
Precipitation (mm)	15	3	8	29	70	164

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	86	86	79	72	55	49	43	38	38	56	75	86
Relative humidity (%)	85	87	85	83	80	77	71	65	61	64	73	82
Wind speed (mph)	7.3	7.2	5.3	4.9	5.9	6.6	7.5	7.9	7.5	6.2	4.9	5.8

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	86	86	79	72	55	49
Relative humidity (%)	85	87	85	83	80	77
Wind speed (mph)	7.3	7.2	5.3	4.9	5.9	6.6

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	43	38	38	56	75	86
Relative humidity (%)	71	65	61	64	73	82
Wind speed (mph)	7.5	7.9	7.5	6.2	4.9	5.8

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 23 years of daily observations at Surabaya/perak, a weather station, about 5 km from the city centre. The underlying daily records come from NOAA's global station network.

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 →