Pematangsiantar weather in January

In January, Pematangsiantar sees average daytime highs of 28°C and overnight lows near 21°C, with 240 mm of rain across 27.9 wet days and about 11.8 hours of daylight. It is the 10th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 1% of the time in January, and the air most often feels oppressive.

Daylight stretches from about 11 h 48 min at the start of January to 11 h 54 min by month's end. Set against the rest of the year, January is Pematangsiantar's 5th-clearest and 2nd-windiest month. For the whole year in context, see Pematangsiantar's year-round climate.

Daytime high
28°
10th warmest
Overnight low
21°
1st coldest
Rainfall
240 mm
27.9 wet days
Daylight
11 h 48 min
6:38 AM – 6:28 PM
Cloud cover
87%
5th clearest
Wind
4 km/h
2nd windiest
Solar energy
4.56 kWh/m²
Travel score
3.5
out of 10

Pematangsiantar is city in North Sumatra Province, Indonesia.

Density
3,491/km²
people per km²
Founded
1871

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical January day in Pematangsiantar reaches about 28°C in the afternoon and slips back to 21°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 29°C. Set against its neighbours, January runs on par with December and on par with February.

15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12821
22821
32821
42821
52821
62821
72821
82821
92821
102821
112821
122821
132821
142821
152821
162821
172821
182821
192821
202821
212821
222821
232821
242821
252821
262821
272821
282821
292821
302821
312821

How January really feels in Pematangsiantar

Once humidity and wind are folded in, January averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

January sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Pematangsiantar weather by month

How January compares with the rest of the year at a glance. January is the 10th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 21°24027.911.83.5
Feb28° / 21°18924.111.93.4
Mar29° / 21°21726.5123.3
Apr29° / 22°24928.612.12.8
May30° / 22°26529.212.12.8
Jun30° / 22°23127.112.23.0
Jul29° / 21°23726.712.23.2
Aug29° / 21°27428.812.13.0
Sep29° / 21°36129.4122.9
Oct28° / 21°37530.211.92.9
Nov28° / 21°35129.411.93.2
Dec28° / 21°31529.611.83.3

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 7% of January, with mostly cloudy or overcast conditions the remaining 92%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1694
2694
3793
4793
5793
6892
7892
8892
9892
10892
11892
12892
13892
14892
15892
16892
17892
18892
19892
20892
21892
22892
23892
24892
25991
26991
27991
28991
29991
301090
311090

Chance of precipitation in January

Any precipitation

Pematangsiantar gets around 240 mm of rain over 27.9 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 90% and peaks near 93% on the wettest days.

0%20%40%60%80%100%151015202531
Rain chance (%)
193
292
392
492
592
691
791
891
991
1091
1191
1291
1391
1491
1591
1691
1791
1890
1990
2090
2189
2289
2389
2489
2588
2688
2788
2888
2987
3087
3187

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

Most of January feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, January lands in the oppressive band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)
13961
24060
34060
44060
54159
64159
74159
84258
94258
104258
114357
124357
134357
144357
154357
164357
174258
184258
194258
204258
214258
224258
234258
244258
254258
264258
274258
284258
294258
304258
314258

Wind in January

Winds average 4 km/h in January.

Across January, daily wind ranges from about 4 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 11 h 48 min at the start of January to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over January. Sunrise moves from 6:32 AM to 6:41 AM, and sunset from 6:22 PM to 6:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:326:22
211.86:326:22
311.86:336:23
411.86:336:23
511.86:346:24
611.86:346:24
711.86:346:25
811.86:356:25
911.86:356:25
1011.86:366:26
1111.86:366:26
1211.86:366:27
1311.86:376:27
1411.86:376:28
1511.86:376:28
1611.86:386:28
1711.86:386:29
1811.86:386:29
1911.96:396:30
2011.96:396:30
2111.96:396:30
2211.96:396:31
2311.96:406:31
2411.96:406:31
2511.96:406:32
2611.96:406:32
2711.96:406:32
2811.96:416:32
2911.96:416:33
3011.96:416:33
3111.96:416:33

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 4.56 kWh/m².

For context, solar energy here swings from a low near 3.99 kWh/m² to a high of 5.21 kWh/m² in March across the year — January's 4.56 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.2Bright
24.3Bright
34.3Bright
44.3Bright
54.3Bright
64.4Bright
74.4Bright
84.4Bright
94.4Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.6Bright
164.6Bright
174.6Bright
184.6Bright
194.6Bright
204.6Bright
214.7Bright
224.7Bright
234.7Bright
244.7Bright
254.7Bright
264.7Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
314.8Bright
Planning a trip in January

Hazard calendar for Pematangsiantar

In seasonPeak

None of Pematangsiantar's seasonal hazards are active in January. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Pematangsiantar sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.

Cyclone
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is January a good time to visit Pematangsiantar?

Our two travel scores rate January for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

3.5
Sightseeing
1st-best month of the year
3.9
Beach & pool
5th-best month of the year

January is a weaker month for outdoor sightseeing in Pematangsiantar.

What to pack for Pematangsiantar in January

From January's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In January, Pematangsiantar sees daytime highs around 28°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 28 days see rain.

light clothesrain gearsun protection

Sea temperature near Pematangsiantar in January

The nearest coast averages about 29°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 57 km away) is warmest in June at about 30°C and coldest in January near 29°C.

The water stays above 20°C all year — warm enough for a swim any month.

28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr30Tropical
May30Tropical
Jun30Tropical
Jul30Tropical
Aug30Tropical
Sep30Tropical
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index in Pematangsiantar in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Pematangsiantar peaks around February 21 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 20 at about 10 (extreme).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeFeb 21UV 15Jun 20UV 10
UV index (midday)Level
Jan13Extreme
Feb15Extreme
Mar14Extreme
Apr13Extreme
May12Extreme
Jun10Extreme
Jul11Extreme
Aug12Extreme
Sep14Extreme
Oct14Extreme
Nov11Extreme
Dec11Extreme

Air quality in Pematangsiantar in January

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where January falls, not just the annual average.

Air quality in Pematangsiantar is worst in October — around 40 µg/m³ PM2.5 (poor), and holds fairly steady the rest of the year.

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModeratePoorModerateOct 1039 µg/m³Dec 1729 µg/m³
PM2.5 (µg/m³)Level
Jan31Moderate
Feb35Moderate
Mar38Poor
Apr36Poor
May34Moderate
Jun33Moderate
Jul33Moderate
Aug34Moderate
Sep39Poor
Oct40Poor
Nov31Moderate
Dec29Moderate
Location & terrain

Where is Pematangsiantar?

Pematangsiantar sits at 3.0°N, 99.1°E, 388 m above sea level, in Indonesia. The nearest listed city is Pekan Bahapal, 21 km away.

Topography around Pematangsiantar

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Pematangsiantar.

Within 3 km, the terrain around Pematangsiantar has only modest variations in elevation — a maximum elevation change of 130 m around an average of 382 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,193 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,429 m.

The land around Pematangsiantar is covered by artificial surfaces (56%) and trees (30%) within 3 km, trees (77%) within 16 km, and trees (70%) within 80 km.

3 km
130 m
16 km
1,193 m
80 km
2,429 m
treesgrasslandcroplandartificial surfaceswater
January weather nearby: Pekan Bahapal 21 km · Tebingtinggi 42 km · Pangururan 57 km · Kisaran 61 km · Tongging 61 km · Paropo 62 km · Kabanjahe 66 km · Berastagi 67 km

Indonesia travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 29% of US
price level, 2025
GDP per capita
$5,060
2025
Happiness
5.6 / 10
World Happiness, 2025
Safe drinking water
30%
of population, 2024
Homicide rate
0.3
per 100k, 2022
Road deaths
11.3
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 471
Religion
Muslim 87%Protestant 8%Roman Catholic 3%Hindu 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Pematangsiantar (2.9595°, 99.0687°, elevation 388 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).