Pematangsiantar climate

Indonesia · 2.96°N, 99.07°E · elevation 388 m · population 279,198

Warmest month
May
high 27 °C81 °F
Coldest month
December
low 21 °C71 °F
Wettest month
October
354 mm14 in
Best time to visit
February
by our comfort score
Annual precipitation
2,724 mm107 in
February driest
Year average
24 °C76 °F
tropical rainforest (Af)

Pematangsiantar (Indonesia) has a tropical rainforest climate (Köppen Af). The average temperature over the year is 24 °C76 °F, and about 2,724 mm107 in of precipitation falls in an average year.

Temperature by month

Average highAverage low
20°25°30°70°80°JFMAMJJASOND27°81°21°70°January: high 26 °C / 79 °F, low 21 °C / 70 °FFebruary: high 27 °C / 81 °F, low 21 °C / 71 °FMarch: high 27 °C / 81 °F, low 22 °C / 71 °FApril: high 27 °C / 81 °F, low 22 °C / 72 °FMay: high 27 °C / 81 °F, low 23 °C / 73 °FJune: high 27 °C / 81 °F, low 22 °C / 72 °FJuly: high 27 °C / 81 °F, low 22 °C / 71 °FAugust: high 27 °C / 81 °F, low 22 °C / 71 °FSeptember: high 27 °C / 80 °F, low 22 °C / 71 °FOctober: high 26 °C / 80 °F, low 22 °C / 71 °FNovember: high 26 °C / 79 °F, low 22 °C / 71 °FDecember: high 26 °C / 79 °F, low 21 °C / 71 °F

Precipitation by month

Precipitation per month (mminches)
010020030040004812JJanuary: 180 mm / 7.1 inFFebruary: 137 mm / 5.4 inMMarch: 188 mm / 7.4 inAApril: 178 mm / 7.0 inMMay: 225 mm / 8.9 inJJune: 156 mm / 6.1 inJJuly: 199 mm / 7.8 inAAugust: 236 mm / 9.3 inSSeptember: 298 mm / 11.7 inOOctober: 354 mm / 14.0 inNNovember: 293 mm / 11.5 inDDecember: 280 mm / 11.0 in35414.0

Pematangsiantar climate table

Monthly averages, 2001–2025
MonthHigh °C°FLow °C°FMean °C°FPrecip. mmin
Jan2679217024751807.1
Feb2781217124761375.4
Mar2781227125761887.4
Apr2781227225771787.0
May2781237325772258.9
Jun2781227225771566.1
Jul2781227125761997.8
Aug2781227125762369.3
Sep27802271247629812
Oct26802271247535414
Nov26792271247529312
Dec26792171247528011
Year2781217024762,724107

“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.

Humidity, cloud, sun and daylight
MonthHumid.CloudSolarDaylight
Jan87%88%4.511:58
Feb85%81%4.912:01
Mar85%82%5.212:06
Apr86%88%5.012:11
May86%88%4.912:15
Jun85%84%4.912:17
Jul84%85%4.912:17
Aug85%88%4.912:13
Sep86%91%4.812:08
Oct87%94%4.512:03
Nov89%94%4.411:59
Dec89%92%4.311:57

Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.

What the climate of Pematangsiantar is like

The warmest month is May, with an average high of 27 °C81 °F and a low of 23 °C73 °F. The coldest is December, when highs average 26 °C79 °F and lows 21 °C71 °F. Temperatures barely change through the year: the warmest and the coolest month differ by only 1.4 °C2.5 °F.

It is very wet, receiving about 2,724 mm107 in of precipitation per year. The wettest three-month stretch is September–November, which brings 35% of the annual total. The wettest month is October (354 mm14 in), the driest is February (137 mm5.4 in).

Relative humidity ranges from 84% in July to 89% in November. The clearest skies (lowest average cloud amount, 81%) are typical of February. Average wind speed near the ground ranges from 3 km/h (2 mph) in June to 4 km/h (2 mph) in January.

Best time to visit Pematangsiantar

Based on these averages, the most comfortable months for sightseeing and outdoor activities are February. Average highs then reach 27 °C81 °F to 27 °C81 °F. Precipitation is 137 mm5.4 in to 137 mm5.4 in per month.

The most challenging month is October, which is very wet (354 mm14 in) and humid (87% relative humidity).

Comfort score: months are ranked by how close they come to an ideal. That means an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.

What to pack for Pematangsiantar

  • Wetter months (August–December) — highs 2679 to 27 °C81 °F, lows 2171 to 22 °C71 °F, about 292 mm12 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and a good rain jacket or umbrella and quick-drying shoes.
  • Drier months (January–July) — highs 2679 to 27 °C81 °F, lows 2170 to 23 °C73 °F, about 180 mm7.1 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an umbrella or light rain jacket.

How Pematangsiantar compares

The nearest larger place is Medan, about 82 km to the northwest. Compared with it, Pematangsiantar is on average 2.4 °C4.2 °F cooler. It receives 20% more precipitation (2,724 mm107 in vs 2,276 mm90 in). The difference is largest in May (2.5 °C4.4 °F cooler).

World Climates covers 110 places in Indonesia. By annual mean temperature, Pematangsiantar is the 100th warmest of them. By annual precipitation, it is the 20th wettest. See all of them on the Indonesia climate page.

Some places in other countries have a very similar pattern of temperature and rainfall. The closest matches are Manolo Fortich (Philippines, Af), Silang (Philippines, Af) and Quezon (Philippines, Af).

The same NASA POWER grid cell also contains Kisaran (pop. 141,915). Their long-term averages in this dataset are essentially the same as for Pematangsiantar, so they do not have separate pages.

Nearby places

All places in Indonesia

Frequently asked questions

What is the warmest month in Pematangsiantar?

May is the warmest month in Pematangsiantar. Its average high is 27 °C (81 °F) and its average low is 23 °C (73 °F).

What is the coldest month in Pematangsiantar?

December is the coldest month. Its average high is 26 °C (79 °F) and its average low is 21 °C (71 °F).

When does it rain the most in Pematangsiantar?

October is the wettest month with about 354 mm (14.0 in) of precipitation. February is the driest with about 137 mm (5.4 in).

What is the best time to visit Pematangsiantar?

Judging by long-term averages, the most comfortable months are February.

About this data

All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station. So they can differ from airport records. The gaps are largest on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.

The grid cell’s average elevation is 162 m, while Pematangsiantar lies at about 388 m. Temperatures on this page were therefore adjusted by −1.5 °C2.6 °F using the standard lapse rate of 6.5 °C per 1,000 m.

Sources and method