Surabaya climate

Name: Surabaya
Address: ID

Surabaya is warmest in October, with average highs of 33 °C, and coldest in July, when nights average 24 °C. January is the wettest month (285 mm) and August the driest (6.5 mm). Figures are 1991–2020 climate normals.

Across a full year Surabaya averages 1,695 mm of rain and 365 days above 25 °C.

Indonesia · population 3,018,022 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month October 33 °C
Coldest month July 24 °C
Driest month August 7 mm
Wettest month January 285 mm
Least cloud August 44 % cloud
Hottest on record December 36 °C
Coldest on record August 21 °C
Warmest sea November 30 °C

What to expectSurabaya through the year

Surabaya changes little through the year. Average daily highs stay between 31 and 33 °C, so no month stands out as a season in the way it would further from the equator.

Counted across a normal year, 365 days a year reach 25 °C, 240 of them reach 30 °C. The warmest reading in the 1991–2020 record is 36 °C, in December.

Rain is strongly seasonal. January averages 285 mm against 7 mm in August — 44 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Surabaya is warmest in November at 30 °C and coldest in August at 28 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	29.4 °C	285 mm	89 %
February	29.4 °C	263 mm	90 %
March	29.8 °C	262 mm	82 %
April	30.1 °C	185 mm	75 %
May	30.5 °C	86 mm	58 %
June	30.4 °C	50 mm	51 %
July	30.6 °C	23 mm	46 %
August	31.4 °C	7 mm	44 %
September	32.7 °C	19 mm	49 %
October	32.9 °C	70 mm	61 %
November	31.4 °C	176 mm	77 %
December	29.9 °C	271 mm	88 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	29.4 °C	24.8 °C	26.6 °C	32.9 °C	23.4 °C	31	9
February	29.4 °C	24.8 °C	26.5 °C	32.0 °C	23.5 °C	28	7
March	29.8 °C	25.0 °C	26.9 °C	32.2 °C	23.2 °C	31	14
April	30.1 °C	25.2 °C	27.3 °C	32.1 °C	23.3 °C	30	17
May	30.5 °C	25.1 °C	27.5 °C	32.4 °C	21.6 °C	31	23
June	30.4 °C	24.5 °C	27.3 °C	32.8 °C	20.9 °C	30	20
July	30.6 °C	23.9 °C	27.1 °C	32.5 °C	20.6 °C	31	24
August	31.4 °C	23.9 °C	27.5 °C	33.3 °C	20.5 °C	31	30
September	32.7 °C	24.4 °C	28.3 °C	34.9 °C	21.2 °C	30	29
October	32.9 °C	25.3 °C	28.7 °C	36.2 °C	21.8 °C	31	29
November	31.4 °C	25.5 °C	28.0 °C	35.7 °C	23.9 °C	30	23
December	29.9 °C	25.1 °C	27.0 °C	36.4 °C	23.6 °C	31	15

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	285 mm	29	13 h/day	89 %	85 %	14 km/h	29.4 °C
February	263 mm	27	12 h/day	90 %	86 %	14 km/h	28.8 °C
March	262 mm	29	12 h/day	82 %	84 %	11 km/h	29.3 °C
April	185 mm	24	12 h/day	75 %	83 %	9.7 km/h	29.9 °C
May	86 mm	14	12 h/day	58 %	80 %	11 km/h	29.8 °C
June	50 mm	9	12 h/day	51 %	77 %	12 km/h	29.1 °C
July	23 mm	4	12 h/day	46 %	73 %	14 km/h	28.4 °C
August	7 mm	1	12 h/day	44 %	68 %	15 km/h	28.1 °C
September	19 mm	3	12 h/day	49 %	66 %	14 km/h	28.4 °C
October	70 mm	11	12 h/day	61 %	69 %	13 km/h	29.1 °C
November	176 mm	23	12 h/day	77 %	77 %	11 km/h	30.0 °C
December	271 mm	28	13 h/day	88 %	83 %	11 km/h	29.7 °C

How Surabaya compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Surabaya	33 °C	24 °C	1,695 mm	365
Pasuruan · Indonesia	32 °C	22 °C	1,710 mm	365
Singosari · Indonesia	30 °C	19 °C	2,303 mm	359
Batu · Indonesia	28 °C	18 °C	3,088 mm	313
Probolinggo · Indonesia	31 °C	24 °C	1,451 mm	365
Malang · Indonesia	30 °C	19 °C	2,341 mm	360
Kediri · Indonesia	31 °C	21 °C	2,075 mm	365

Where Surabaya ranks

Ranking	Position	Value
Warmest sea temperatures in Asia in November	5th of 50	30 °C
Warmest sea temperatures in the world in November	5th of 50	30 °C
Warmest sea temperatures in Asia in December	6th of 50	30 °C
Warmest sea temperatures in Asia in January	8th of 50	29 °C
Warmest sea temperatures in the world in December	8th of 50	30 °C
Warmest sea temperatures in the world in January	10th of 50	29 °C

Planning a trip? See the best time to visit Surabaya.

QuestionsCommon questions about Surabaya’s climate

When is the best time to visit Surabaya?

That depends on what you want, so the honest answer is a comparison rather than a single month. January, February, March sit closest to 20 °C on average, October is the warmest month and August the driest. The month-by-month table above has the full picture.

How hot does Surabaya get?

In October, the warmest month, daily highs average 33 °C. About 240 days a year pass 30 °C. The highest value in the 1991–2020 record is 36 °C.

How cold does it get in winter?

Nights average 24 °C in July, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Surabaya?

January, averaging 285 mm over 29 days with rain. The driest month is August with 7 mm. The year as a whole averages 1,695 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Surabaya rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: -7.249°, 112.751° (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.