Siem Reap weather in December

In December, Siem Reap sees average daytime highs of 30°C and overnight lows near 23°C, with 16 mm of rain across 2.9 wet days and about 11.2 hours of daylight. It is the 12th-warmest and 10th-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 38% of the time in December, and the air most often feels muggy.

Daylight stretches from about 11 h 18 min at the start of December to 11 h 12 min by month's end. Set against the rest of the year, December is Siem Reap's 4th-clearest and 4th-windiest month. For the whole year in context, see Siem Reap's year-round climate.

Daytime high
30°
12th warmest
Overnight low
23°
2nd coldest
Rainfall
16 mm
2.9 wet days
Daylight
11 h 12 min
6:24 AM – 5:37 PM
Cloud cover
52%
4th clearest
Wind
9 km/h
4th windiest
Solar energy
4.82 kWh/m²
Travel score
5.7
out of 10

Siem Reap is capital of the same named Cambodian province.

Founded
~802 CE

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

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 Siem Reap reaches about 30°C in the afternoon and slips back to 23°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 33°C. Set against its neighbours, December runs on par with November and about 1°C cooler than January.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13124
23124
33124
43123
53023
63023
73023
83023
93023
103023
113023
123023
133023
143023
153023
163023
173023
183022
193022
203022
213022
223022
233022
243022
253022
263022
273022
283022
293022
303022
313022

How December really feels in Siem Reap

Once humidity and wind are folded in, December averages 14 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
14
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.

Siem Reap weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°91.911.35.5
Feb33° / 24°132.611.64.5
Mar34° / 26°527.811.93.2
Apr35° / 27°9413.512.32.5
May34° / 27°14821.412.62.2
Jun33° / 27°13220.712.82.4
Jul32° / 27°13522.112.72.6
Aug32° / 26°16224.412.42.4
Sep31° / 26°24425.912.12.5
Oct31° / 25°22423.311.73.1
Nov31° / 24°628.811.44.7
Dec30° / 23°162.911.25.7

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 38% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 21% of December, with mostly cloudy or overcast conditions the remaining 40%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15743
25743
35743
45743
55743
65743
75743
85743
95743
105743
115644
125644
135743
145743
155743
165842
175842
185842
196040
206040
216139
226139
236238
246238
256337
266436
276535
286535
296634
306733
316733

Chance of precipitation in December

Any precipitation

Siem Reap gets around 16 mm of rain over 2.9 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 9% and peaks near 17% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202531
Rain chance (%)
117
216
316
415
515
614
714
813
913
1012
1111
1211
1310
149
159
168
178
187
197
207
216
226
236
245
255
265
275
285
295
305
315

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the muggy band about 34% of days. Sticky, muggy-or-worse air turns up on roughly 73% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
10210304216
20310314115
30311324114
40311324013
50312334012
60312343911
70313353910
8041435389
9041536379
10041636368
11041736367
12041836357
13151935346
14152035346
15162134335
16162234325
17172333315
18172433315
19272432304
20282532294
21282632284
22292732273
23292732273
24292833263
25292833252
26292834252
27292835252
28192736252
29192737251
30182738251
31182639251

Wind in December

Winds average 9 km/h in December.

Across December, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
288calm
298calm
308calm
318calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 11 h 18 min at the start of December to 11 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:16 AM to 6:31 AM, and sunset from 5:32 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.36:165:32
211.36:175:33
311.36:175:33
411.36:185:33
511.26:185:33
611.26:195:34
711.26:195:34
811.26:205:34
911.26:215:35
1011.26:215:35
1111.26:225:35
1211.26:225:36
1311.26:235:36
1411.26:235:36
1511.26:245:37
1611.26:245:37
1711.26:255:38
1811.26:255:38
1911.26:265:39
2011.26:265:39
2111.26:275:39
2211.26:275:40
2311.26:285:40
2411.26:285:41
2511.26:295:41
2611.26:295:42
2711.26:295:42
2811.26:305:43
2911.26:305:43
3011.26:315:44
3111.26:315:44

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.82 kWh/m².

For context, solar energy here swings from a low near 4.62 kWh/m² to a high of 6.16 kWh/m² in April across the year — December's 4.82 kWh/m² sits near the bottom.

0246151015202531
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
114.8Bright
124.8Bright
134.8Bright
144.8Bright
154.8Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.8Bright
214.9Bright
224.9Bright
234.9Bright
244.9Bright
254.9Bright
264.9Bright
275.0Bright
285.0Bright
295.0Bright
305.0Bright
315.0Bright
Planning a trip in December

Hazard calendar for Siem Reap

In seasonPeak

In December, Siem Reap sits inside its pacific typhoon season. The full year is below, with each hazard's peak months called out.

Siem Reap sits in the Pacific typhoon belt; the season peaks July–October.

Siem Reap's rainy season runs May–October, when most of the year's rain falls.

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

Is December a good time to visit Siem Reap?

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

5.7
Sightseeing
1st-best month of the year
7.9
Beach & pool
2nd-best month of the year

December is a reasonable time to visit Siem Reap for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Siem Reap in December

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

In December, Siem Reap sees daytime highs around 30°C and nights near 23°C. Pack light clothes. Worth having: sun protection.

light clothessun protection

UV index in Siem Reap in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Siem Reap peaks around August 16 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 22 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 16UV 14Nov 22UV 8
UV index (midday)Level
Jan10Very high
Feb10Very high
Mar12Extreme
Apr12Extreme
May11Extreme
Jun12Extreme
Jul13Extreme
Aug14Extreme
Sep12Extreme
Oct11Extreme
Nov8Very high
Dec8Very high

Air quality in Siem Reap 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 Siem Reap is worst in February — around 40 µg/m³ PM2.5 (poor), about 2.9× the cleanest month (November, 14 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateFeb 2240 µg/m³Nov 2214 µg/m³
PM2.5 (µg/m³)Level
Jan29Moderate
Feb40Poor
Mar40Poor
Apr37Poor
May19Moderate
Jun15Moderate
Jul16Moderate
Aug15Moderate
Sep15Moderate
Oct17Moderate
Nov14Moderate
Dec14Moderate
Location & terrain

Where is Siem Reap?

Siem Reap sits at 13.4°N, 103.9°E, 18 m above sea level, in Cambodia. The nearest listed city is Yeang, 34 km away.

YeangPhum Ânlŭng VĭlBattambangPhumĭ TnaôtPursatSamraongSisophonAnlong Veaeng

Topography around Siem Reap

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

Within 3 km, the terrain around Siem Reap has only modest variations in elevation — a maximum elevation change of 28 m around an average of 17 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 123 m; within 80 km, significant variations in elevation — a maximum elevation change of 484 m.

The land around Siem Reap is covered by artificial surfaces (60%) and trees (24%) within 3 km, cropland (45%) and trees (30%) within 16 km, and cropland (48%) and trees (30%) within 80 km.

3 km
28 m
16 km
123 m
80 km
484 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
December weather nearby: Yeang 34 km · Phum Ânlŭng Vĭl 74 km · Battambang 77 km · Phumĭ Tnaôt 89 km · Pursat 92 km · Samraong 98 km · Sisophon 99 km · Anlong Veaeng 100 km

Cambodia travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / C / G
230 V · 50 Hz
Prices
≈ 34% of US
price level, 2025
GDP per capita
$2,872
2025
Happiness
4.5 / 10
World Happiness, 2025
Safe drinking water
30%
of population, 2024
Homicide rate
1.8
per 100k, 2011
Road deaths
19.6
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
Very low
EF EPI 390
Religion
Buddhist 97%Muslim 2%other 1%Christian 0%

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 Siem Reap (13.3618°, 103.8606°, 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). 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).