Slawi weather in December

In December, Slawi sees average daytime highs of 29°C and overnight lows near 24°C, with 459 mm of rain across 29.9 wet days and about 12.4 hours of daylight. It is the 7th-warmest and 2nd-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 0% of the time in December, and the air most often feels oppressive.

Daylight stretches from about 12 h 24 min at the start of December to 12 h 24 min by month's end. Set against the rest of the year, December is Slawi's 10th-clearest and 7th-windiest month. For the whole year in context, see Slawi's year-round climate.

Daytime high
29°
7th warmest
Overnight low
24°
8th coldest
Rainfall
459 mm
29.9 wet days
Daylight
12 h 24 min
5:27 AM – 5:52 PM
Cloud cover
92%
10th clearest
Wind
4 km/h
7th windiest
Solar energy
4.67 kWh/m²
Travel score
2.8
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical December day in Slawi reaches about 29°C in the afternoon and slips back to 24°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 30°C. Set against its neighbours, December runs on par with November and on par with January.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12924
22924
32924
42924
52924
62924
72924
82924
92924
102924
112924
122924
132924
142924
152924
162924
172924
182924
192924
202924
212924
222924
232924
242924
252924
262924
272924
282924
292924
302924
312924

How December really feels in Slawi

Once humidity and wind are folded in, December 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 December is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Slawi weather by month

How December compares with the rest of the year at a glance. December is the 7th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 24°47230.412.42.9
Feb29° / 24°44327.712.22.8
Mar29° / 24°41530.5122.8
Apr30° / 24°31228.111.92.9
May30° / 24°16622.111.73.7
Jun29° / 24°9915.111.64.7
Jul29° / 23°6410.811.65.6
Aug29° / 22°397.511.85.9
Sep29° / 23°6310125.2
Oct30° / 24°17119.812.23.9
Nov29° / 24°35027.412.33.0
Dec29° / 24°45929.912.42.8

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 0% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 3% of December, with mostly cloudy or overcast conditions the remaining 97%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1397
2397
3397
4298
5298
6298
7298
8298
9298
10298
11298
12298
13298
14397
15397
16397
17397
18397
19496
20496
21496
22496
23496
24496
25496
26496
27496
28496
29496
30595
31595

Chance of precipitation in December

Any precipitation

Slawi gets around 459 mm of rain over 29.9 wet days in December. 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 (%)
194
294
395
495
595
695
796
896
996
1097
1197
1297
1397
1498
1598
1698
1798
1898
1997
2097
2197
2297
2397
2497
2597
2697
2797
2897
2997
3097
3197

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the oppressive band about 95% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
10955
20955
30955
40955
50955
60955
70955
80955
90955
100955
110955
120955
130955
140955
150964
160964
170964
180964
190973
200973
210973
220973
230973
240973
250973
260973
271963
281963
291963
301954
311954

Wind in December

Winds average 4 km/h in December.

Across December, 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 December

DaylightNight

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

Days grow by about 0 minutes over December. Sunrise moves from 5:22 AM to 5:35 AM, and sunset from 5:44 PM to 5:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:225:44
212.45:225:45
312.45:235:45
412.45:235:46
512.45:235:46
612.45:245:47
712.45:245:47
812.45:245:48
912.45:255:48
1012.45:255:49
1112.45:255:49
1212.45:265:50
1312.45:265:50
1412.45:275:51
1512.45:275:51
1612.45:275:52
1712.45:285:52
1812.45:285:53
1912.45:295:53
2012.45:295:54
2112.45:305:54
2212.45:305:55
2312.45:315:55
2412.45:315:56
2512.45:325:56
2612.45:325:56
2712.45:335:57
2812.45:335:57
2912.45:345:58
3012.45:345:58
3112.45:355:59

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.67 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.67 kWh/m² to a high of 5.95 kWh/m² in September across the year — December's 4.67 kWh/m² sits near the bottom.

024151015202531
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.7Bright
54.7Bright
64.7Bright
74.7Bright
84.7Bright
94.7Bright
104.7Bright
114.7Bright
124.7Bright
134.7Bright
144.7Bright
154.7Bright
164.7Bright
174.7Bright
184.7Bright
194.7Bright
204.7Bright
214.7Bright
224.7Bright
234.7Bright
244.7Bright
254.7Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.7Bright
314.7Bright
Planning a trip in December

Hazard calendar for Slawi

In seasonPeak

In December, Slawi sits inside its cyclone and rainy season season. The full year is below, with each hazard's peak months called out.

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

Slawi's rainy season runs November–April, when most of the year's rain falls.

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

Is December a good time to visit Slawi?

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

2.8
Sightseeing
10th-best month of the year
3.7
Beach & pool
9th-best month of the year

December is a weaker month for outdoor sightseeing in Slawi.

What to pack for Slawi in December

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

In December, Slawi sees daytime highs around 29°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 Slawi in December

The nearest coast averages about 30°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore 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
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov30Tropical
Dec30Tropical

UV index in Slawi in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Slawi peaks around March 15 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 16 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 15UV 14Nov 16UV 6
UV index (midday)Level
Jan12Extreme
Feb12Extreme
Mar14Extreme
Apr11Extreme
May8Very high
Jun8Very high
Jul9Very high
Aug11Extreme
Sep12Extreme
Oct11Extreme
Nov6High
Dec12Extreme

Air quality in Slawi in December

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Slawi is worst in May — around 42 µg/m³ PM2.5 (poor), and holds fairly steady the rest of the year.

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModeratePoorModerateMay 1641 µg/m³Feb 1231 µg/m³
PM2.5 (µg/m³)Level
Jan33Moderate
Feb31Moderate
Mar37Poor
Apr38Poor
May42Poor
Jun38Poor
Jul35Moderate
Aug35Moderate
Sep36Poor
Oct37Poor
Nov34Moderate
Dec33Moderate
Location & terrain

Where is Slawi?

Slawi sits at 7.0°S, 109.1°E, 43 m above sea level, in Indonesia. The nearest listed city is Adiwerna, 5.0 km away.

Topography around Slawi

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

Within 3 km, the terrain around Slawi has only modest variations in elevation — a maximum elevation change of 45 m around an average of 40 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 764 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,396 m.

The land around Slawi is covered by artificial surfaces (37%), trees (36%) and cropland (21%) within 3 km, cropland (37%) and trees (35%) within 16 km, and trees (47%) and water (29%) within 80 km.

3 km
45 m
16 km
764 m
80 km
3,396 m
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Adiwerna 5.0 km · Tarub 6.0 km · Lebaksiu 8.0 km · Balapulang 9.0 km · Dukuhturi 11 km · Tegal 12 km · Margasari 18 km · Bulakamba 24 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 Slawi (-6.9816°, 109.1407°, elevation 43 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).