Sầm Sơn weather in December

In December, Sầm Sơn sees average daytime highs of 21°C and overnight lows near 18°C, with 54 mm of rain across 8.9 wet days and about 10.8 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 22°C in the first days to 20°C by the end. The sky is clear or mostly clear about 31% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 h 54 min at the start of December to 10 h 48 min by month's end. Set against the rest of the year, December is Sầm Sơn's 3rd-clearest and 1st-windiest month. For the whole year in context, see Sầm Sơn's year-round climate.

Daytime high
21°
10th warmest
Overnight low
18°
3rd coldest
Rainfall
54 mm
8.9 wet days
Daylight
10 h 48 min
6:28 AM – 5:17 PM
Cloud cover
63%
3rd clearest
Wind
18 km/h
1st windiest
Solar energy
2.78 kWh/m²
Travel score
6.5
out of 10

Sầm Sơn is city in Thanh Hóa province.

Density
2,888/km²
people per km²
Founded
1981

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 22°C in the first days to 20°C by the end.

A typical December day in Sầm Sơn reaches about 21°C in the afternoon and slips back to 18°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 23°C. Set against its neighbours, December runs about 3°C cooler than November and about 2°C warmer than January.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
12220
22220
32219
42219
52219
62219
72219
82119
92119
102119
112118
122118
132118
142118
152118
162118
172118
182018
192018
202018
212018
222018
232018
242017
252017
262017
272017
282017
292017
302017
312017

How December really feels in Sầm Sơn

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.

Sầm Sơn weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan19° / 17°5510.610.95.9
Feb20° / 18°368.411.36.1
Mar22° / 20°529.711.96.4
Apr25° / 23°627.512.47.0
May28° / 26°13912.212.95.5
Jun30° / 28°1461113.24.3
Jul30° / 28°21212.713.14.2
Aug30° / 28°31220.112.73.7
Sep29° / 26°36820.212.14.1
Oct27° / 24°24116.211.55.7
Nov24° / 22°829.911.16.9
Dec21° / 18°548.910.86.5

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 13% of December, with mostly cloudy or overcast conditions the remaining 57%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24753
34753
44654
54456
64456
74357
84258
94159
104060
114060
124060
134159
144258
154258
164258
174357
184357
194456
204456
214456
224555
234555
244456
254456
264555
274555
284456
294357
304258
314159

Chance of precipitation in December

Any precipitation

Sầm Sơn gets around 54 mm of rain over 8.9 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 29% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
131
231
330
430
530
629
729
828
928
1027
1127
1226
1326
1425
1525
1625
1725
1826
1926
2027
2127
2228
2328
2429
2530
2630
2731
2832
2933
3034
3134

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the dry band about 30% of days. Sticky, muggy-or-worse air turns up on roughly 28% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
116222224141
217222224131
319222223121
420232223111
521232222111
622232222101
72423222191
82523222190
92723212080
102823212080
113022202070
123122202070
133321192070
143421192070
153521191970
163520191970
173620191970
183620191970
193620191960
203720191860
213720201860
223720201850
233720211850
243620211940
253620211940
263520222030
273420222130
283320222230
293220222320
303220222320
313120222420

Wind in December

Winds average 18 km/h in December, the windiest month of the year.

Across December, daily wind ranges from about 17 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
118light breeze
218light breeze
318light breeze
418light breeze
518light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light breeze
1917light breeze
2017light breeze
2117light breeze
2217light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2817light breeze
2917light breeze
3017light breeze
3117light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 54 min at the start of December to 10 h 48 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 6:19 AM to 6:35 AM, and sunset from 5:13 PM to 5:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.96:195:13
210.96:205:13
310.96:215:13
410.96:215:13
510.96:225:14
610.96:225:14
710.96:235:14
810.86:245:14
910.86:245:15
1010.86:255:15
1110.86:255:15
1210.86:265:16
1310.86:265:16
1410.86:275:16
1510.86:285:17
1610.86:285:17
1710.86:295:17
1810.86:295:18
1910.86:305:18
2010.86:305:19
2110.86:315:19
2210.86:315:20
2310.86:325:20
2410.86:325:21
2510.86:335:21
2610.86:335:22
2710.86:335:22
2810.86:345:23
2910.86:345:23
3010.86:355:24
3110.86:355:24

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.78 kWh/m².

For context, solar energy here swings from a low near 2.6 kWh/m² to a high of 5.55 kWh/m² in May across the year — December's 2.78 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.9Moderate
22.9Moderate
32.9Moderate
42.9Moderate
52.8Moderate
62.8Moderate
72.8Moderate
82.8Moderate
92.8Moderate
102.8Moderate
112.8Moderate
122.8Moderate
132.8Moderate
142.8Moderate
152.8Moderate
162.8Moderate
172.8Moderate
182.8Moderate
192.8Moderate
202.8Moderate
212.8Moderate
222.8Moderate
232.8Moderate
242.8Moderate
252.8Moderate
262.8Moderate
272.8Moderate
282.8Moderate
292.7Moderate
302.7Moderate
312.7Moderate
Planning a trip in December

Hazard calendar for Sầm Sơn

In seasonPeak

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

Sầm Sơn sits in the Pacific typhoon belt; the season peaks July–October.

Sầm Sơn's monsoon runs July–October, when most of the year's rain falls.

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

Is December a good time to visit Sầm Sơn?

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

6.5
Sightseeing
3rd-best month of the year
3.9
Beach & pool
10th-best month of the year

December is a reasonable time to visit Sầm Sơn for sightseeing.

What to pack for Sầm Sơn in December

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

In December, Sầm Sơn sees daytime highs around 21°C and nights near 18°C. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near Sầm Sơn in December

The nearest coast averages about 23°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 August at about 30°C and coldest in February near 21°C.

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

20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb21Refreshing
Mar21Refreshing
Apr24Refreshing
May28Warm
Jun29Tropical
Jul30Tropical
Aug30Tropical
Sep30Tropical
Oct28Warm
Nov26Warm
Dec23Refreshing

UV index in Sầm Sơn in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Sầm Sơn peaks around August 11 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highHighAug 11UV 12Dec 16UV 6
UV index (midday)Level
Jan7Very high
Feb9Very high
Mar10Very high
Apr9Very high
May10Extreme
Jun12Extreme
Jul12Extreme
Aug13Extreme
Sep10Very high
Oct9Very high
Nov7Very high
Dec6High

Air quality in Sầm Sơn 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 Sầm Sơn is worst in April — around 65 µg/m³ PM2.5 (unhealthy), about 3.3× the cleanest month (July, 20 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyPoorModeratePoorUnhealthyApr 1065 µg/m³Jul 1920 µg/m³
PM2.5 (µg/m³)Level
Jan65Unhealthy
Feb63Unhealthy
Mar63Unhealthy
Apr65Unhealthy
May43Poor
Jun25Moderate
Jul20Moderate
Aug23Moderate
Sep33Moderate
Oct46Poor
Nov55Poor
Dec64Unhealthy
Location & terrain

Where is Sầm Sơn?

Sầm Sơn sits at 19.7°N, 105.9°E, 10 m above sea level, in Vietnam. The nearest listed city is Thanh Hóa, 16 km away.

Topography around Sầm Sơn

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

Within 3 km, the terrain around Sầm Sơn has only modest variations in elevation — a maximum elevation change of 78 m around an average of 3 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 176 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,500 m.

The land around Sầm Sơn is covered by water (58%) within 3 km, water (60%) within 16 km, and trees (39%), water (33%) and cropland (22%) within 80 km.

3 km
78 m
16 km
176 m
80 km
1,500 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Thanh Hóa 16 km · Nga Sơn 31 km · Bỉm Sơn 39 km · Nghi Sơn 46 km · Thị Trấn Lam Sơn 55 km · Hoàng Mai 55 km · Ninh Binh 59 km · Nam Định 83 km

Vietnam travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C / F
220 V · 50 Hz
Prices
≈ 29% of US
price level, 2025
GDP per capita
$5,066
2025
Happiness
6.4 / 10
World Happiness, 2025
Safe drinking water
59%
of population, 2024
Homicide rate
1.5
per 100k, 2011
Road deaths
30.6
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 500
Religion
none 86%Catholic 6%Buddhist 6%Protestant 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 Sầm Sơn (19.7333°, 105.9°, elevation 10 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).