Diễn Thành weather in December

In December, Diễn Thành sees average daytime highs of 22°C and overnight lows near 17°C, with 26 mm of rain across 5.1 wet days and about 10.9 hours of daylight. It is the 11th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 23°C in the first days to 22°C by the end. The sky is clear or mostly clear about 19% 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 54 min by month's end. Set against the rest of the year, December is Diễn Thành's 5th-clearest and 3rd-windiest month. For the whole year in context, see Diễn Thành's year-round climate.

Daytime high
22°
11th warmest
Overnight low
17°
2nd coldest
Rainfall
26 mm
5.1 wet days
Daylight
10 h 54 min
6:28 AM – 5:20 PM
Cloud cover
71%
5th clearest
Wind
9 km/h
3rd windiest
Solar energy
2.48 kWh/m²
Travel score
7.2
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 23°C in the first days to 22°C by the end.

A typical December day in Diễn Thành reaches about 22°C in the afternoon and slips back to 17°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 27°C. Set against its neighbours, December runs about 3°C cooler than November and about 1°C warmer than January.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12418
22418
32418
42318
52318
62318
72317
82317
92317
102317
112217
122217
132217
142217
152217
162216
172216
182216
192216
202216
212216
222216
232216
242216
252216
262216
272216
282216
292216
302216
312216

How December really feels in Diễn Thành

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.

Diễn Thành weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan21° / 16°173.9117.0
Feb23° / 17°133.311.47.4
Mar26° / 19°315.311.97.2
Apr30° / 23°496.912.45.3
May33° / 26°1151412.93.1
Jun35° / 28°1161213.12.1
Jul34° / 28°17114.2132.3
Aug33° / 27°25920.512.62.6
Sep31° / 25°29319.912.13.2
Oct29° / 23°23817.511.64.8
Nov26° / 20°629.111.16.7
Dec22° / 17°265.110.97.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% 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 67%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13466
23367
33268
43268
53268
63169
73169
83169
93070
103070
113070
123070
133169
143169
153268
163268
173367
183466
193466
203565
213565
223466
233466
243466
253466
263565
273565
283565
293268
303268
313070

Chance of precipitation in December

Any precipitation

Diễn Thành gets around 26 mm of rain over 5.1 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 16% and peaks near 24% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
124
223
323
422
521
619
718
818
917
1016
1115
1214
1313
1412
1512
1612
1712
1812
1912
2013
2113
2214
2314
2415
2515
2616
2716
2817
2917
3017
3117

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 27% of days. Sticky, muggy-or-worse air turns up on roughly 29% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
114192526142
215192525132
316202625122
417202625112
518202624102
61920262491
72020262391
82220262381
92320262281
102420262171
112620252171
122720242171
132920232170
143020232070
153120222070
163219212070
173220212070
183320212070
193320211970
203320211970
213320211970
223420211960
233420211960
243320212050
253320222050
263221222140
273221232230
283121232230
293021232320
302921242420
312921242520

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
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
318calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 54 min at the start of December to 10 h 54 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 6:19 AM to 6:35 AM, and sunset from 5:16 PM to 5:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.96:195:16
210.96:205:16
310.96:205:16
410.96:215:16
510.96:225:16
610.96:225:16
710.96:235:17
810.96:235:17
910.96:245:17
1010.96:255:18
1110.96:255:18
1210.96:265:18
1310.96:265:19
1410.96:275:19
1510.96:275:19
1610.96:285:20
1710.96:285:20
1810.96:295:20
1910.96:295:21
2010.96:305:21
2110.96:305:22
2210.96:315:22
2310.96:315:23
2410.96:325:23
2510.96:325:24
2610.96:335:24
2710.96:335:25
2810.96:335:25
2910.96:345:26
3010.96:345:26
3110.96:355:27

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.48 kWh/m².

For context, solar energy here swings from a low near 2.47 kWh/m² to a high of 5.73 kWh/m² in June across the year — December's 2.48 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.6Moderate
22.6Moderate
32.6Moderate
42.5Moderate
52.5Moderate
62.5Moderate
72.5Moderate
82.5Moderate
92.5Moderate
102.5Moderate
112.5Moderate
122.5Moderate
132.5Moderate
142.5Moderate
152.5Moderate
162.5Moderate
172.5Moderate
182.5Moderate
192.5Moderate
202.5Moderate
212.5Moderate
222.5Moderate
232.5Moderate
242.5Moderate
252.5Moderate
262.5Moderate
272.5Moderate
282.5Moderate
292.5Moderate
302.5Moderate
312.5Moderate
Planning a trip in December

Hazard calendar for Diễn Thành

In seasonPeak

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

Diễn Thành sits in the Pacific typhoon belt; the season peaks July–October.

Diễn Thành'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 Diễn Thành?

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

7.2
Sightseeing
2nd-best month of the year
5.2
Beach & pool
7th-best month of the year

December is one of the better times to visit Diễn Thành for general sightseeing.

What to pack for Diễn Thành in December

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

In December, Diễn Thành sees daytime highs around 22°C and nights near 17°C. Worth packing: light clothes. About 5 days see rain.

light clothes

Sea temperature near Diễn Thành 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
Mar22Refreshing
Apr24Warm
May28Warm
Jun30Tropical
Jul30Tropical
Aug30Tropical
Sep30Tropical
Oct28Warm
Nov26Warm
Dec23Refreshing

UV index in Diễn Thành 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 Diễn Thành peaks around July 17 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 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 highHighJul 17UV 12Dec 14UV 6
UV index (midday)Level
Jan8Very high
Feb9Very high
Mar10Very high
Apr9Very high
May11Extreme
Jun12Extreme
Jul12Extreme
Aug12Extreme
Sep11Extreme
Oct10Very high
Nov7High
Dec6High

Air quality in Diễn Thành 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 Diễn Thành is worst in April — around 62 µg/m³ PM2.5 (unhealthy), about 3.5× the cleanest month (July, 18 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecPoorUnhealthyPoorModeratePoorApr 1161 µg/m³Jul 1618 µg/m³
PM2.5 (µg/m³)Level
Jan52Poor
Feb52Poor
Mar57Unhealthy
Apr62Unhealthy
May35Poor
Jun20Moderate
Jul18Moderate
Aug21Moderate
Sep30Moderate
Oct41Poor
Nov47Poor
Dec52Poor
Location & terrain

Where is Diễn Thành?

Diễn Thành sits at 19.0°N, 105.6°E, 9 m above sea level, in Vietnam. The nearest listed city is Kim Liên, 32 km away.

Topography around Diễn Thành

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

Within 3 km, the terrain around Diễn Thành has only modest variations in elevation — a maximum elevation change of 12 m around an average of 3 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 430 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,711 m.

The land around Diễn Thành is covered by cropland (44%) and artificial surfaces (21%) within 3 km, water (35%), cropland (33%) and trees (20%) within 16 km, and trees (54%) and water (28%) within 80 km.

3 km
12 m
16 km
430 m
80 km
1,711 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
December weather nearby: Kim Liên 32 km · Hoàng Mai 35 km · Vinh 35 km · Yên Vinh 35 km · Bến Thủy 38 km · Nghi Xuân 39 km · Nghi Sơn 45 km · Hồng Lĩnh 51 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 Diễn Thành (18.9765°, 105.6003°, elevation 9 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).