Sầm Sơn weather in May

In May, Sầm Sơn sees average daytime highs of 28°C and overnight lows near 26°C, with 139 mm of rain across 12.2 wet days and about 12.9 hours of daylight. It is the 5th-warmest and 6th-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 19% of the time in May, and the air most often feels miserable.

Daylight stretches from about 12 h 42 min at the start of May to 13 h 06 min by month's end. Set against the rest of the year, May is Sầm Sơn's 6th-clearest and 6th-windiest month. For the whole year in context, see Sầm Sơn's year-round climate.

Daytime high
28°
5th warmest
Overnight low
26°
8th coldest
Rainfall
139 mm
12.2 wet days
Daylight
12 h 54 min
5:25 AM – 6:21 PM
Cloud cover
70%
6th clearest
Wind
16 km/h
6th windiest
Solar energy
5.55 kWh/m²
Travel score
5.5
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 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 Sầm Sơn reaches about 28°C in the afternoon and slips back to 26°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)
12725
22725
32725
42725
52725
62726
72726
82826
92826
102826
112826
122826
132826
142826
152826
162826
172826
182827
192927
202927
212927
222927
232927
242927
252927
262927
272927
282927
292927
302927
313028

How May really feels in Sầm Sơn

Once humidity and wind are folded in, May averages 21 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
21
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.

Sầm Sơn weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 6th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 65%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14654
24654
34654
44555
54654
64654
74555
84555
94456
104258
114258
124159
134060
143961
153763
163664
173466
183367
193268
203070
212971
222872
232773
242575
252575
262575
272476
282476
292377
302278
312278

Chance of precipitation in May

Any precipitation

Sầm Sơn gets around 139 mm of rain over 12.2 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 39% and peaks near 43% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
131
232
333
434
534
635
736
837
937
1038
1138
1239
1339
1439
1540
1640
1740
1841
1941
2041
2141
2242
2342
2442
2542
2643
2743
2843
2943
3043
3142

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 72% of days. Sticky, muggy-or-worse air turns up on roughly 98% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
104103056
203102958
30392860
40392662
50392563
60382465
70282367
80282268
91272169
101272070
111271971
121271971
131271971
141271971
150171873
160171874
170171874
180171874
190171874
200171775
210171775
220171775
230161677
240161677
250161578
260151579
270151480
280041383
290041383
300031285
310031186

Wind in May

Winds average 16 km/h in May.

Across May, daily wind ranges from about 16 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
116light breeze
216light breeze
317light breeze
417light breeze
517light breeze
617light breeze
717light breeze
817light breeze
917light breeze
1017light breeze
1117light breeze
1217light breeze
1317light breeze
1417light breeze
1517light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze
3116light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 42 min at the start of May to 13 h 06 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 5:32 AM to 5:21 AM, and sunset from 6:15 PM to 6:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:326:15
212.75:326:15
312.75:316:16
412.85:316:16
512.85:306:16
612.85:296:17
712.85:296:17
812.85:286:17
912.85:286:18
1012.85:276:18
1112.95:276:19
1212.95:266:19
1312.95:266:19
1412.95:266:20
1512.95:256:20
1612.95:256:21
1712.95:246:21
1813.05:246:21
1913.05:246:22
2013.05:236:22
2113.05:236:23
2213.05:236:23
2313.05:226:23
2413.05:226:24
2513.05:226:24
2613.05:226:25
2713.15:226:25
2813.15:216:25
2913.15:216:26
3013.15:216:26
3113.15:216:27

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.55 kWh/m² — the sunniest month for solar.

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 — May's 5.55 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.6Bright
115.6Bright
125.6Bright
135.6Bright
145.6Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.6Bright
265.6Bright
275.6Bright
285.6Bright
295.6Bright
305.6Bright
315.6Bright
Planning a trip in May

Hazard calendar for Sầm Sơn

In seasonPeak

In May, 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 May a good time to visit Sầm Sơn?

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

5.5
Sightseeing
8th-best month of the year
6.3
Beach & pool
1st-best month of the year

May is a reasonable time to visit Sầm Sơn for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Sầm Sơn in May

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

In May, Sầm Sơn sees daytime highs around 28°C and nights near 26°C. Pack light clothes. Worth having: rain gear and sun protection. About 12 days see rain.

light clothesrain gearsun protection

Sea temperature near Sầm Sơn in May

The nearest coast averages about 28°C in May — 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 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 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 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 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
May 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).