Semarang weather in January

In January, Semarang sees average daytime highs of 30°C and overnight lows near 24°C, with 391 mm of rain across 29.9 wet days and about 12.4 hours of daylight. It is the 11th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°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 12 h 24 min at the start of January to 12 h 18 min by month's end. Set against the rest of the year, January is Semarang's 10th-clearest and 2nd-windiest month. For the whole year in context, see Semarang's year-round climate.

Daytime high
30°
11th warmest
Overnight low
24°
6th coldest
Rainfall
391 mm
29.9 wet days
Daylight
12 h 24 min
5:37 AM – 5:59 PM
Cloud cover
90%
10th clearest
Wind
7 km/h
2nd windiest
Solar energy
4.66 kWh/m²
Travel score
2.7
out of 10

Semarang is city in Central Java Province, Indonesia.

Density
4,534/km²
people per km²
Founded
1547

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 30°C through the month.

A typical January day in Semarang reaches about 30°C in the afternoon and slips back to 24°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 31°C. Set against its neighbours, January runs about 1°C cooler than December and on par with February.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13024
23024
33024
43024
53024
63024
73024
83024
93024
103024
113024
123024
133024
143024
153024
163024
173024
182924
192924
202924
212924
222924
232924
242924
252924
262924
272924
282924
292924
302924
312924

How January really feels in Semarang

Once humidity and wind are folded in, January averages 31 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
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in January is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Semarang weather by month

How January compares with the rest of the year at a glance. January is the 11th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 24°39129.912.42.7
Feb30° / 24°35427.212.22.7
Mar30° / 24°34529.3122.6
Apr31° / 24°2372611.92.7
May32° / 24°10216.411.73.5
Jun32° / 24°6010.511.64.0
Jul32° / 23°386.511.64.3
Aug33° / 23°23411.84.2
Sep33° / 24°446.1123.7
Oct33° / 24°13915.312.23.0
Nov32° / 24°28225.612.32.5
Dec30° / 24°41629.212.42.6

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 6% of January, with mostly cloudy or overcast conditions the remaining 93%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1793
2892
3892
4892
5892
6892
7892
8991
9991
10991
11991
12991
13991
14991
15991
16892
17892
18892
19793
20793
21793
22793
23694
24595
25496
26496
27496
28496
29397
30397
31397

Chance of precipitation in January

Any precipitation

Semarang gets around 391 mm of rain over 29.9 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 97% and peaks near 98% on the wettest days.

0%20%40%60%80%100%151015202531
Rain chance (%)
195
295
395
495
596
696
796
896
996
1096
1196
1296
1396
1496
1596
1697
1797
1897
1997
2097
2197
2297
2397
2497
2597
2697
2797
2898
2998
3098
3198

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 68% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
16634
26733
36832
46832
56832
66931
76931
86931
97030
107030
117030
127030
137030
147030
157030
166931
176931
186832
196832
206733
216733
226634
236634
246634
256634
266634
276733
286733
296832
306832
316931

Wind in January

Winds average 7 km/h in January.

Across January, daily wind ranges from about 6 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 12 h 24 min at the start of January to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over January. Sunrise moves from 5:29 AM to 5:42 AM, and sunset from 5:53 PM to 6:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:295:53
212.45:305:54
312.45:305:54
412.45:315:55
512.45:315:55
612.45:325:55
712.45:325:56
812.45:335:56
912.45:335:56
1012.45:345:57
1112.45:345:57
1212.45:355:57
1312.45:355:58
1412.45:365:58
1512.45:365:58
1612.45:375:59
1712.45:375:59
1812.45:385:59
1912.45:385:59
2012.45:385:59
2112.35:396:00
2212.35:396:00
2312.35:406:00
2412.35:406:00
2512.35:406:00
2612.35:416:00
2712.35:416:01
2812.35:416:01
2912.35:426:01
3012.35:426:01
3112.35:426:01

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 4.66 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.66 kWh/m² to a high of 6.31 kWh/m² in September across the year — January's 4.66 kWh/m² sits near the bottom.

024151015202531
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.8Bright
54.8Bright
64.8Bright
74.8Bright
84.8Bright
94.8Bright
104.8Bright
114.7Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.7Bright
174.7Bright
184.6Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
314.5Bright
Planning a trip in January

Hazard calendar for Semarang

In seasonPeak

In January, Semarang sits inside its cyclone and monsoon season. The full year is below, with each hazard's peak months called out.

Semarang sits in the South Indian Ocean cyclone belt; the season peaks January–March.

Semarang's monsoon runs November–April, when most of the year's rain falls.

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

Is January a good time to visit Semarang?

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

2.7
Sightseeing
7th-best month of the year
3.6
Beach & pool
11th-best month of the year

January is a weaker month for outdoor sightseeing in Semarang.

What to pack for Semarang in January

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

In January, Semarang sees daytime highs around 30°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 30 days see rain.

light clothesrain gearsun protection

Sea temperature near Semarang 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 14 km away) is warmest in May at about 30°C and coldest in February 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
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov30Tropical
Dec30Tropical

UV index in Semarang in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Semarang peaks around March 15 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 14 at about 7 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeVery highExtremeMar 15UV 14Nov 14UV 7
UV index (midday)Level
Jan11Extreme
Feb12Extreme
Mar14Extreme
Apr11Extreme
May8Very high
Jun8Very high
Jul9Very high
Aug11Extreme
Sep12Extreme
Oct10Very high
Nov7High
Dec12Extreme

Air quality in Semarang 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 Semarang is worst in May — around 45 µg/m³ PM2.5 (poor), and holds fairly steady the rest of the year.

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorMay 1445 µg/m³Feb 1131 µg/m³
PM2.5 (µg/m³)Level
Jan33Moderate
Feb30Moderate
Mar38Poor
Apr43Poor
May45Poor
Jun41Poor
Jul36Poor
Aug36Poor
Sep38Poor
Oct39Poor
Nov38Poor
Dec34Moderate
Location & terrain

Where is Semarang?

Semarang sits at 7.0°S, 110.4°E, 18 m above sea level, in Indonesia. The nearest listed city is Mranggen, 11 km away.

Topography around Semarang

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

Within 3 km, the terrain around Semarang has only modest variations in elevation — a maximum elevation change of 133 m around an average of 26 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 616 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,293 m.

The land around Semarang is covered by artificial surfaces (84%) within 3 km, water (31%), trees (30%) and artificial surfaces (25%) within 16 km, and trees (48%) and water (25%) within 80 km.

3 km
133 m
16 km
616 m
80 km
3,293 m
treesgrasslandcroplandartificial surfaceswaterwetland
January weather nearby: Mranggen 11 km · Ungaran 16 km · Demak 27 km · Ambarawa 30 km · Salatiga 39 km · Welahan 39 km · Weleri 39 km · Pecangaan 46 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 Semarang (-6.9931°, 110.4208°, elevation 18 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).