Home › Cities › Indonesia › Pematangsiantar

Pematangsiantar, Indonesia climate

Aw Tropical savanna (dry winter)

Pematangsiantar has a remarkably steady tropical climate (Tropical savanna (dry winter), Köppen Aw). The hottest month is May with an average daily high near 91°F, while the coldest is December averaging around 74°F at night. Around 43 inches of precipitation falls each year, peaking in August (5.8 inches) and easing off in February (1.8 inches).

☀️ All year

Hot

Daytime highs near 91°F most of the year.

About 151 days a year above 90 °F

🌙 Nights

Stays warm

Even the coolest nights stay near 74°F.

🌧️ Rain

Wet

About 43 in of rain a year.

Wettest in August

⛅ Sky & trend

Often grey

Overcast skies dominate much of the year.

+0.4 °F vs 50 years ago

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Clear vs cloudy days

Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day counts

Pematangsiantar climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	88	89	91	91	91	91	91	90	89	89	88	87
Avg temp (°F)	81	82	83	83	83	83	82	82	82	81	81	81
Avg low (°F)	74	74	75	75	75	75	74	74	74	74	74	74
Precipitation (in)	2.4	1.8	2.5	2.9	2.2	4.3	2.1	5.8	5.6	4.6	5.2	3.6

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°F)	88	89	91	91	91	91
Avg temp (°F)	81	82	83	83	83	83
Avg low (°F)	74	74	75	75	75	75
Precipitation (in)	2.4	1.8	2.5	2.9	2.2	4.3

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°F)	91	90	89	89	88	87
Avg temp (°F)	82	82	82	81	81	81
Avg low (°F)	74	74	74	74	74	74
Precipitation (in)	2.1	5.8	5.6	4.6	5.2	3.6

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	2	2	1	2	2	2	2	3	3	3	4	4
Days with high ≥ 90°F (days)	7	11	18	18	18	18	17	16	11	8	6	4

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	2	2	1	2	2	2
Days with high ≥ 90°F (days)	7	11	18	18	18	18

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	2	3	3	3	4	4
Days with high ≥ 90°F (days)	17	16	11	8	6	4

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	83	79	80	84	86	83	84	89	90	91	92	90
Clear days (≤ 30% cloud)	0.5	0.7	0.9	0.4	0.4	0.7	0.6	0.1	0.0	0.0	0.0	0.1
Partly cloudy days (30–70%)	6	7	7	5	4	6	5	3	2	2	2	3
Cloudy days (≥ 70%)	24	20	23	25	26	24	25	28	28	29	28	28
Relative humidity (%)	88	86	85	85	85	84	83	84	85	87	89	89
Wind speed (mph)	3.0	2.9	2.8	2.5	2.3	2.3	2.3	2.4	2.3	2.5	2.6	3.0

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	83	79	80	84	86	83
Clear days (≤ 30% cloud)	0.5	0.7	0.9	0.4	0.4	0.7
Partly cloudy days (30–70%)	6	7	7	5	4	6
Cloudy days (≥ 70%)	24	20	23	25	26	24
Relative humidity (%)	88	86	85	85	85	84
Wind speed (mph)	3.0	2.9	2.8	2.5	2.3	2.3

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	84	89	90	91	92	90
Clear days (≤ 30% cloud)	0.6	0.1	0.0	0.0	0.0	0.1
Partly cloudy days (30–70%)	5	3	2	2	2	3
Cloudy days (≥ 70%)	25	28	28	29	28	28
Relative humidity (%)	83	84	85	87	89	89
Wind speed (mph)	2.3	2.4	2.3	2.5	2.6	3.0

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 26 years of daily observations at Polonia, a weather station, about 80 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 →