Climate averages 1991–2020
Pematangsiantar weather
in December.
A warm, very wet month: the coolest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a warm month in Pematangsiantar: daytime highs average 26.3°C and nights cool to about 20.5°C. By daytime temperature it is the coolest month of the year.
Expect about 315 mm of rain on roughly 30 days, which makes December a very wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 57 min on an average December day.
The nearest other city in this atlas is Tebingtinggi (42 km away). In December its highs average 28.1°C, 1.8°C warmer than Pematangsiantar, with 258 mm of rain.
Among the 200 cities listed in Indonesia, Pematangsiantar ranks joint 185th of 200 for the warmest December highs and joint 82nd of 200 for the driest December (rainfall, lowest first). The mean December high of those 200 cities is 28.4°C; Pematangsiantar is 2.1°C cooler than that mean.
From December to January, average highs rise by 0.3°C to 26.6°C, and monthly rainfall falls from 315 mm to 240 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Pematangsiantar climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 26.6°C20.2°C | 20.2°C | 240 | 27.9 | 12.012 h |
| February | 27.1°C20.2°C | 20.2°C | 190 | 24.3 | 12.012 h |
| March | 27.8°C20.7°C | 20.7°C | 217 | 26.4 | 12.112 h |
| April | 27.9°C21.0°C | 21.0°C | 249 | 28.6 | 12.212 h |
| May | 28.2°C21.3°C | 21.3°C | 265 | 29.2 | 12.312 h |
| June | 28.3°C21.1°C | 21.1°C | 231 | 27.1 | 12.312 h |
| July | 28.1°C20.8°C | 20.8°C | 236 | 26.7 | 12.312 h |
| August | 27.9°C20.7°C | 20.7°C | 274 | 28.7 | 12.212 h |
| September | 27.5°C20.6°C | 20.6°C | 361 | 29.4 | 12.112 h |
| October | 27.1°C20.6°C | 20.6°C | 375 | 30.2 | 12.112 h |
| November | 26.6°C20.6°C | 20.6°C | 351 | 29.4 | 12.012 h |
| December, selected | 26.3°C20.5°C | 20.5°C | 315 | 29.6 | 12.012 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Tebingtinggi in DecemberIndonesia · 42 kmHigh 28.1°C · Low 23.1°C · 258 mm rain
- Kisaran in DecemberIndonesia · 61 kmHigh 28.5°C · Low 23.1°C · 298 mm rain
- Kabanjahe in DecemberIndonesia · 66 kmHigh 23.7°C · Low 17.4°C · 298 mm rain
- Perbaungan in DecemberIndonesia · 69 kmHigh 28.1°C · Low 23.5°C · 310 mm rain
- Percut in DecemberIndonesia · 77 kmHigh 28.1°C · Low 23.0°C · 347 mm rain
- Tanjungbalai in DecemberIndonesia · 81 kmHigh 28.4°C · Low 23.9°C · 333 mm rain
- Medan in DecemberIndonesia · 82 kmHigh 28.2°C · Low 22.4°C · 302 mm rain
- Sunggal in DecemberIndonesia · 85 kmHigh 28.1°C · Low 22.1°C · 345 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Pematangsiantar) is explained once on the Pematangsiantar year overview and on the Sources, method and limits page.