Móng Cái weather in May

In May, Móng Cái sees average daytime highs of 28°C and overnight lows near 25°C, with 209 mm of rain across 19 wet days and about 13 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 27°C in the first days to 29°C by the end. The sky is clear or mostly clear about 16% of the time in May, and the air most often feels miserable.

Daylight stretches from about 12 h 48 min at the start of May to 13 h 12 min by month's end. Set against the rest of the year, May is Móng Cái's 9th-clearest and 8th-windiest month. For the whole year in context, see Móng Cái's year-round climate.

Daytime high
28°
5th warmest
Overnight low
25°
8th coldest
Rainfall
209 mm
19 wet days
Daylight
13 hours
5:14 AM – 6:15 PM
Cloud cover
72%
9th clearest
Wind
13 km/h
8th windiest
Solar energy
5.1 kWh/m²
Travel score
4.8
out of 10

Móng Cái is provincial city of Vietnam.

Density
211/km²
people per km²

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 27°C in the first days to 29°C by the end.

A typical May day in Móng Cái reaches about 28°C in the afternoon and slips back to 25°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 30°C. Set against its neighbours, May runs about 3°C warmer than April and about 2°C cooler than June.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12624
22724
32724
42724
52724
62725
72725
82725
92725
102725
112725
122825
132825
142825
152825
162825
172825
182826
192826
202826
212826
222826
232826
242826
252926
262926
272926
282926
292926
302926
312926

How May really feels in Móng Cái

Once humidity and wind are folded in, May 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 May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Móng Cái weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan17° / 14°6912.710.85.0
Feb18° / 15°501111.35.4
Mar21° / 18°7413.111.85.7
Apr24° / 22°7112.712.56.2
May28° / 25°20919134.8
Jun30° / 27°28823.513.33.4
Jul30° / 27°3802513.23.2
Aug30° / 27°37424.612.73.3
Sep29° / 26°25318.612.14.3
Oct27° / 24°9910.311.56.7
Nov23° / 20°679.1117.1
Dec19° / 16°538.810.76.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 16% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 69%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23862
33862
43862
54060
63961
73961
83961
93961
103862
113862
123862
133664
143664
153565
163367
173268
183169
193070
202872
212773
222674
232377
242377
252278
262179
272179
281981
291981
301882
311882

Chance of precipitation in May

Any precipitation

Móng Cái gets around 209 mm of rain over 19 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 61% and peaks near 72% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
148
249
351
452
553
654
755
856
956
1057
1158
1258
1359
1460
1560
1661
1761
1862
1963
2063
2164
2265
2366
2467
2567
2668
2769
2870
2970
3071
3172

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the miserable band about 59% of days. Sticky, muggy-or-worse air turns up on roughly 97% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
116153741
216143643
315143545
415143447
515133249
614133151
714123053
814123053
913122955
1013122856
1113112857
1213112857
1313112857
1413112857
1512102859
1612102859
1712102859
181292860
191292860
201292761
210282763
220282664
230282664
240272566
250172468
260162370
270162271
280152173
290152074
300141976
310141778

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 13 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 48 min at the start of May to 13 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 24 minutes over May. Sunrise moves from 5:22 AM to 5:09 AM, and sunset from 6:09 PM to 6:22 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:226:09
212.85:216:09
312.85:216:10
412.85:206:10
512.95:196:10
612.95:196:11
712.95:186:11
812.95:186:12
912.95:176:12
1012.95:166:12
1112.95:166:13
1213.05:156:13
1313.05:156:14
1413.05:156:14
1513.05:146:15
1613.05:146:15
1713.05:136:16
1813.15:136:16
1913.15:126:16
2013.15:126:17
2113.15:126:17
2213.15:116:18
2313.15:116:18
2413.15:116:19
2513.15:116:19
2613.25:106:20
2713.25:106:20
2813.25:106:20
2913.25:106:21
3013.25:106:21
3113.25:096:22

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.1 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.69 kWh/m² to a high of 5.1 kWh/m² in May across the year — May's 5.1 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.1Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.2Bright
85.2Bright
95.2Bright
105.2Bright
115.2Bright
125.2Bright
135.2Bright
145.2Bright
155.1Bright
165.1Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.1Bright
245.1Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
295.0Bright
305.0Bright
315.0Bright
Planning a trip in May

Hazard calendar for Móng Cái

In seasonPeak

In May, Móng Cái sits inside its pacific typhoon and monsoon season. The full year is below, with each hazard's peak months called out.

Móng Cái sits in the Pacific typhoon belt; the season peaks July–October.

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

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

Is May a good time to visit Móng Cái?

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

4.8
Sightseeing
8th-best month of the year
5.3
Beach & pool
4th-best month of the year

May is a reasonable time to visit Móng Cái for sightseeing.

What to pack for Móng Cái in May

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

In May, Móng Cái sees daytime highs around 28°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 19 days see rain.

light clothesrain gearsun protection

Sea temperature near Móng Cái in May

The nearest coast averages about 27°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 19 km away) is warmest in August at about 30°C and coldest in February near 19°C.

It's comfortable for a long swim from Mar 15 to Dec 30 — about 9.6 months when the water holds above 20°C.

20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan19Cool
Feb19Cool
Mar20Refreshing
Apr23Refreshing
May27Warm
Jun29Tropical
Jul29Tropical
Aug30Tropical
Sep29Tropical
Oct27Warm
Nov24Warm
Dec21Refreshing

UV index in Móng Cái in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Móng Cái peaks around July 9 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJul 9UV 12Dec 17UV 6
UV index (midday)Level
Jan6High
Feb8Very high
Mar9Very high
Apr8Very high
May10Very high
Jun12Extreme
Jul12Extreme
Aug8Very high
Sep9Very high
Oct9Very high
Nov7High
Dec6High

Air quality in Móng Cái in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Móng Cái is worst in December — around 46 µg/m³ PM2.5 (poor), about 2.8× the cleanest month (July, 16 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModeratePoorDec 2346 µg/m³Jul 1416 µg/m³
PM2.5 (µg/m³)Level
Jan45Poor
Feb42Poor
Mar44Poor
Apr38Poor
May25Moderate
Jun17Moderate
Jul16Moderate
Aug18Moderate
Sep25Moderate
Oct32Moderate
Nov35Moderate
Dec46Poor
Location & terrain

Where is Móng Cái?

Móng Cái sits at 21.5°N, 108.0°E, 9 m above sea level, in Vietnam. The nearest listed city is Thị Trấn Đầm Hà, 43 km away.

Cẩm PhảThị Trấn Na DươngHa LongLạng Sơn

Topography around Móng Cái

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

Within 3 km, the terrain around Móng Cái has only modest variations in elevation — a maximum elevation change of 43 m around an average of 8 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 367 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,472 m.

The land around Móng Cái is covered by artificial surfaces (38%) and trees (24%) within 3 km, water (44%) and trees (38%) within 16 km, and trees (53%) and water (40%) within 80 km.

3 km
43 m
16 km
367 m
80 km
1,472 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
May weather nearby: Thị Trấn Đầm Hà 43 km · Thị Trấn Tiên Yên 62 km · Thị Trấn Ba Chẽ 76 km · Cẩm Phả Mines 89 km · Cẩm Phả 92 km · Thị Trấn Na Dương 106 km · Ha Long 112 km · Lạng Sơn 130 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 Móng Cái (21.5247°, 107.9662°, 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).