Lasem weather in December

In December, Lasem sees average daytime highs of 30°C and overnight lows near 25°C, with 281 mm of rain across 28.3 wet days and about 12.4 hours of daylight. It is the 9th-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 2% 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 Lasem's 11th-clearest and 7th-windiest month. For the whole year in context, see Lasem's year-round climate.

Daytime high
30°
9th warmest
Overnight low
25°
8th coldest
Rainfall
281 mm
28.3 wet days
Daylight
12 h 24 min
5:19 AM – 5:42 PM
Cloud cover
88%
11th clearest
Wind
10 km/h
7th windiest
Solar energy
5.14 kWh/m²
Travel score
2.9
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical December day in Lasem reaches about 30°C in the afternoon and slips back to 25°C overnight — a 4°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, December runs on par with November and on par with January.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13025
23025
33025
43025
53025
63025
73025
83025
93025
103025
113025
123025
133025
143025
153025
163025
173025
183025
193025
203025
213025
223025
233025
243025
253025
262925
272925
282925
292925
302925
312925

How December really feels in Lasem

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.

Lasem weather by month

How December compares with the rest of the year at a glance. December is the 9th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 25°28428.912.32.9
Feb29° / 25°24926.412.22.9
Mar29° / 25°23128.1123.0
Apr30° / 26°19224.511.93.3
May30° / 26°10016.811.74.3
Jun30° / 25°6410.711.65.0
Jul30° / 25°355.811.75.7
Aug30° / 24°133.411.85.9
Sep31° / 25°254.5125.4
Oct31° / 25°8713.212.14.3
Nov30° / 25°18923.412.33.2
Dec30° / 25°28128.312.42.9

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 2% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 7% of December, with mostly cloudy or overcast conditions the remaining 91%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11288
21288
31189
41189
51189
61189
71090
81090
91090
101090
111090
12991
13991
14991
15991
16991
17892
18793
19793
20793
21793
22793
23793
24793
25793
26892
27892
28892
29892
30892
31991

Chance of precipitation in December

Any precipitation

Lasem gets around 281 mm of rain over 28.3 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 91% and peaks near 92% on the wettest days.

0%20%40%60%80%100%151015202531
Rain chance (%)
188
289
389
490
590
690
791
891
991
1091
1192
1292
1392
1492
1592
1692
1792
1892
1992
2092
2191
2291
2391
2491
2591
2691
2791
2892
2992
3092
3192

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 54% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
15545
25545
35446
45347
55248
65248
75149
85149
95050
105050
115050
125050
135149
145149
155248
165248
175347
185446
195446
205545
215644
225743
235743
245842
255842
265941
275941
286040
296040
306040
316139

Wind in December

Winds average 10 km/h in December.

Across December, daily wind ranges from about 8 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3112calm

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 5:13 AM to 5:26 AM, and sunset from 5:35 PM to 5:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.45:135:35
212.45:135:35
312.45:145:36
412.45:145:36
512.45:145:37
612.45:155:37
712.45:155:38
812.45:155:38
912.45:165:39
1012.45:165:39
1112.45:175:40
1212.45:175:40
1312.45:175:40
1412.45:185:41
1512.45:185:41
1612.45:195:42
1712.45:195:42
1812.45:205:43
1912.45:205:43
2012.45:215:44
2112.45:215:44
2212.45:215:45
2312.45:225:45
2412.45:225:46
2512.45:235:46
2612.45:235:47
2712.45:245:47
2812.45:245:48
2912.45:255:48
3012.45:255:48
3112.45:265:49

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 5.14 kWh/m².

For context, solar energy here swings from a low near 4.98 kWh/m² to a high of 6.76 kWh/m² in September across the year — December's 5.14 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.2Bright
95.2Bright
105.2Bright
115.2Bright
125.2Bright
135.1Bright
145.1Bright
155.1Bright
165.1Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.1Bright
245.1Bright
255.1Bright
265.1Bright
275.1Bright
285.1Bright
295.1Bright
305.1Bright
315.1Bright
Planning a trip in December

Hazard calendar for Lasem

In seasonPeak

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

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

Lasem'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 Lasem?

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

2.9
Sightseeing
10th-best month of the year
3.9
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Lasem.

What to pack for Lasem in December

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

In December, Lasem sees daytime highs around 30°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 28 days see rain.

light clothesrain gearsun protection

Sea temperature near Lasem 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 November at about 30°C and coldest in August near 28°C.

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

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr30Tropical
May30Tropical
Jun29Tropical
Jul29Tropical
Aug28Tropical
Sep29Tropical
Oct29Tropical
Nov30Tropical
Dec30Tropical

UV index in Lasem in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December 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 Lasem peaks around March 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 16 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeVery highMar 17UV 14Jun 16UV 8
UV index (midday)Level
Jan10Extreme
Feb10Extreme
Mar14Extreme
Apr11Extreme
May9Very high
Jun8Very high
Jul9Very high
Aug11Extreme
Sep12Extreme
Oct12Extreme
Nov7Very high
Dec11Extreme

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

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModeratePoorModerateMay 1839 µg/m³Feb 1126 µg/m³
PM2.5 (µg/m³)Level
Jan27Moderate
Feb25Moderate
Mar32Moderate
Apr35Poor
May40Poor
Jun37Poor
Jul34Moderate
Aug33Moderate
Sep35Poor
Oct39Poor
Nov34Moderate
Dec30Moderate
Location & terrain

Where is Lasem?

Lasem sits at 6.7°S, 111.5°E, 12 m above sea level, in Indonesia. The nearest listed city is Rembangan, 12 km away.

Topography around Lasem

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

Within 3 km, the terrain around Lasem has significant variations in elevation — a maximum elevation change of 251 m around an average of 28 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 787 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,559 m.

The land around Lasem is covered by trees (38%) and cropland (21%) within 3 km, water (40%) and trees (34%) within 16 km, and water (36%), trees (35%) and cropland (24%) within 80 km.

3 km
251 m
16 km
787 m
80 km
1,559 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Rembangan 12 km · Blora 31 km · Juwana 33 km · Pati 46 km · Tayu 47 km · Cepu 53 km · Jekulo 59 km · Baekrajan 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 Lasem (-6.6922°, 111.4527°, elevation 12 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).