Pematangsiantar climate

Name: Pematangsiantar
Address: ID

Pematangsiantar is warmest in June, with average highs of 28 °C, and coldest in January, when nights average 20 °C. October is the wettest month (367 mm) and February the driest (189 mm). Figures are 1991–2020 climate normals.

Across a full year Pematangsiantar averages 3,293 mm of rain and 352 days above 25 °C.

Indonesia · population 279,198 · 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 June 28 °C
Coldest month January 20 °C
Driest month February 189 mm
Wettest month October 367 mm
Least cloud February 81 % cloud
Hottest on record August 33 °C
Coldest on record February 17 °C

What to expectPematangsiantar through the year

Pematangsiantar changes little through the year. Average daily highs stay between 27 and 28 °C, so no month stands out as a season in the way it would further from the equator.

Counted across a normal year, 352 days a year reach 25 °C, 8 of them reach 30 °C. The warmest reading in the 1991–2020 record is 33 °C, in August.

Rain is spread fairly evenly through the year, from 189 mm in February to 367 mm in October. There is no dry season to aim for.

Month by month

Month	Avg high	Rainfall	Cloud
January	26.6 °C	241 mm	85 %
February	27.2 °C	189 mm	81 %
March	27.8 °C	226 mm	83 %
April	27.9 °C	256 mm	89 %
May	28.2 °C	260 mm	90 %
June	28.3 °C	223 mm	84 %
July	28.1 °C	234 mm	84 %
August	28.0 °C	271 mm	88 %
September	27.6 °C	356 mm	91 %
October	27.1 °C	367 mm	93 %
November	26.6 °C	355 mm	94 %
December	26.3 °C	314 mm	92 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	26.6 °C	20.1 °C	22.9 °C	29.5 °C	17.8 °C	29	0
February	27.2 °C	20.1 °C	23.2 °C	30.0 °C	17.2 °C	28	0
March	27.8 °C	20.6 °C	23.7 °C	30.8 °C	18.4 °C	31	0
April	27.9 °C	21.0 °C	23.9 °C	30.9 °C	19.0 °C	30	0
May	28.2 °C	21.3 °C	24.2 °C	31.8 °C	19.0 °C	31	2
June	28.3 °C	21.1 °C	24.1 °C	31.5 °C	18.9 °C	30	2
July	28.1 °C	20.7 °C	23.9 °C	31.8 °C	18.0 °C	30	2
August	28.0 °C	20.6 °C	23.7 °C	32.6 °C	18.5 °C	31	2
September	27.6 °C	20.6 °C	23.4 °C	30.9 °C	18.7 °C	29	0
October	27.1 °C	20.6 °C	23.2 °C	31.3 °C	18.8 °C	30	0
November	26.6 °C	20.6 °C	23.0 °C	30.9 °C	18.9 °C	28	0
December	26.3 °C	20.4 °C	22.9 °C	29.8 °C	18.3 °C	27	0

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	241 mm	27	12 h/day	85 %	89 %	8.8 km/h
February	189 mm	24	12 h/day	81 %	88 %	9.1 km/h
March	226 mm	27	12 h/day	83 %	88 %	8.8 km/h
April	256 mm	29	12 h/day	89 %	89 %	8.4 km/h
May	260 mm	29	12 h/day	90 %	90 %	7.7 km/h
June	223 mm	26	12 h/day	84 %	89 %	7.6 km/h
July	234 mm	26	12 h/day	84 %	88 %	7.5 km/h
August	271 mm	28	12 h/day	88 %	89 %	7.6 km/h
September	356 mm	29	12 h/day	91 %	90 %	7.8 km/h
October	367 mm	30	12 h/day	93 %	91 %	7.9 km/h
November	355 mm	29	12 h/day	94 %	92 %	8.0 km/h
December	314 mm	29	12 h/day	92 %	91 %	8.8 km/h

How Pematangsiantar 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
Pematangsiantar	28 °C	20 °C	3,293 mm	352
Perbaungan · Indonesia	30 °C	23 °C	2,632 mm	364
Percut · Indonesia	30 °C	23 °C	3,221 mm	364
Tanjungbalai · Indonesia	30 °C	24 °C	3,111 mm	365
Medan · Indonesia	30 °C	22 °C	3,278 mm	364
Sunggal · Indonesia	30 °C	22 °C	3,176 mm	364
Binjai · Indonesia	31 °C	21 °C	3,209 mm	363

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

QuestionsCommon questions about Pematangsiantar’s climate

When is the best time to visit Pematangsiantar?

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

How hot does Pematangsiantar get?

In June, the warmest month, daily highs average 28 °C. About 8 days a year pass 30 °C. The highest value in the 1991–2020 record is 33 °C.

How cold does it get in winter?

Nights average 20 °C in January, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Pematangsiantar?

October, averaging 367 mm over 30 days with rain. The driest month is February with 189 mm. The year as a whole averages 3,293 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 Pematangsiantar 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
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.