Nam Som weather in December

In December, Nam Som sees average daytime highs of 28°C and overnight lows near 17°C, with 9 mm of rain across 1.3 wet days and about 11 hours of daylight. It is the 12th-warmest and 12th-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 63% of the time in December, and the air most often feels humid.

Daylight stretches from about 11 hours at the start of December to 10 h 54 min by month's end. Set against the rest of the year, December is Nam Som's 3rd-clearest and 4th-windiest month. For the whole year in context, see Nam Som's year-round climate.

Daytime high
28°
12th warmest
Overnight low
17°
2nd coldest
Rainfall
9 mm
1.3 wet days
Daylight
10 h 54 min
6:39 AM – 5:36 PM
Cloud cover
33%
3rd clearest
Wind
6 km/h
4th windiest
Solar energy
4.51 kWh/m²
Travel score
7.7
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

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

A typical December day in Nam Som reaches about 28°C in the afternoon and slips back to 17°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 31°C. Set against its neighbours, December runs about 2°C cooler than November and on par with January.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12919
22919
32919
42918
52918
62918
72918
82918
92918
102818
112818
122817
132817
142817
152817
162817
172817
182817
192817
202817
212817
222816
232816
242816
252816
262816
272816
282816
292816
302816
312816

How December really feels in Nam Som

Once humidity and wind are folded in, December 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

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

Nam Som weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 17°101.611.17.1
Feb31° / 18°142.411.45.5
Mar34° / 22°396.911.93.6
Apr35° / 24°7812.812.42.5
May33° / 25°23623.112.82.3
Jun32° / 25°23122.8132.4
Jul32° / 25°26824.9132.5
Aug31° / 25°32626.312.62.6
Sep31° / 24°26624.412.12.8
Oct31° / 23°10512.311.64.4
Nov30° / 20°232.911.26.1
Dec28° / 17°91.3117.7

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 63% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 19%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17723
27723
37822
47822
57822
67822
77822
87723
97822
107822
118020
128020
138119
148119
158218
168317
178317
188416
198416
208416
218416
228416
238416
248416
258218
268218
278218
288119
298020
307921
317921

Chance of precipitation in December

Any precipitation

Nam Som gets around 9 mm of rain over 1.3 wet days in December, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 4% and peaks near 5% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
15
25
35
45
55
64
74
84
94
103
113
123
133
142
152
162
172
183
193
203
214
224
234
244
255
265
275
285
295
305
315

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the humid band about 32% of days. Sticky, muggy-or-worse air turns up on roughly 26% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1816323410
281633339
391733329
491834318
5101834308
6101935297
7112035277
8112136266
9122236255
10132236245
11142336234
12152435233
13162434223
14172534222
15192533212
16202532212
17212531212
18222630212
19232629211
20242629201
21242628201
22252728191
23252728191
24252728181
25252829181
26242830181
27242830171
28232831171
29222932171
30212933171
31192934171

Wind in December

Winds average 6 km/h in December.

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

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 11 hours at the start of December to 10 h 54 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 6:31 AM to 6:46 AM, and sunset from 5:31 PM to 5:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.06:315:31
211.06:315:32
311.06:325:32
411.06:325:32
511.06:335:32
611.06:345:32
711.06:345:33
811.06:355:33
911.06:355:33
1011.06:365:34
1111.06:365:34
1211.06:375:34
1310.96:385:35
1410.96:385:35
1510.96:395:35
1610.96:395:36
1710.96:405:36
1810.96:405:36
1910.96:415:37
2010.96:415:37
2110.96:425:38
2210.96:425:38
2310.96:435:39
2410.96:435:39
2510.96:445:40
2610.96:445:40
2710.96:445:41
2810.96:455:41
2910.96:455:42
3010.96:465:42
3110.96:465:43

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.51 kWh/m².

For context, solar energy here swings from a low near 4.2 kWh/m² to a high of 6.03 kWh/m² in April across the year — December's 4.51 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.5Bright
174.5Bright
184.5Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.6Bright
314.6Bright
Planning a trip in December

Hazard calendar for Nam Som

In seasonPeak

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

Nam Som's monsoon runs May–September, when most of the year's rain falls.

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

Is December a good time to visit Nam Som?

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

7.7
Sightseeing
1st-best month of the year
8.7
Beach & pool
2nd-best month of the year

December is one of the better times to visit Nam Som for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Nam Som in December

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

In December, Nam Som sees daytime highs around 28°C and nights near 17°C. Pack light clothes. Worth having: sun protection.

light clothessun protection

UV index in Nam Som in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Nam Som peaks around August 12 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 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 12UV 13Dec 14UV 8
UV index (midday)Level
Jan9Very high
Feb10Very high
Mar12Extreme
Apr11Extreme
May11Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Extreme
Nov8Very high
Dec8Very high

Air quality in Nam Som 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 Nam Som is worst in April — around 122 µg/m³ PM2.5 (unhealthy), about 8.3× the cleanest month (November, 15 µg/m³).

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

0306090120150JanFebMarAprMayJunJulAugSepOctNovDecModerateUnhealthyModerateApr 11119 µg/m³Nov 1615 µg/m³
PM2.5 (µg/m³)Level
Jan22Moderate
Feb37Poor
Mar108Unhealthy
Apr122Unhealthy
May28Moderate
Jun16Moderate
Jul15Moderate
Aug16Moderate
Sep15Moderate
Oct16Moderate
Nov15Moderate
Dec17Moderate
Location & terrain

Where is Nam Som?

Nam Som sits at 17.8°N, 102.2°E, 231 m above sea level, in Thailand. The nearest listed city is Tha Bo, 42 km away.

Topography around Nam Som

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

Within 3 km, the terrain around Nam Som has only modest variations in elevation — a maximum elevation change of 156 m around an average of 227 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 559 m; within 80 km, large variations in elevation — a maximum elevation change of 951 m.

The land around Nam Som is covered by trees (51%) and cropland (36%) within 3 km, trees (66%) and cropland (28%) within 16 km, and trees (59%) and cropland (34%) within 80 km.

3 km
156 m
16 km
559 m
80 km
951 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Tha Bo 42 km · Vientiane 49 km · Na Klang 52 km · Kut Chap 55 km · Erawan 58 km · Loei 58 km · Nong Khai 60 km · Nong Bua Lamphu 68 km

Thailand travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 31% of US
price level, 2025
GDP per capita
$8,057
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
4.8
per 100k, 2011
Road deaths
32.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 402
Religion
Buddhist 93%Muslim 5%Christian 1%other 1%

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 Nam Som (17.7704°, 102.1895°, elevation 231 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. 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).