Diễn Thành weather in May

In May, Diễn Thành sees average daytime highs of 33°C and overnight lows near 26°C, with 115 mm of rain across 14 wet days and about 12.9 hours of daylight. It is the 3rd-warmest and 6th-wettest month of the year here.

Highs climb over the month, from about 32°C in the first days to 34°C by the end. The sky is clear or mostly clear about 15% 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 hours by month's end. Set against the rest of the year, May is Diễn Thành's 6th-clearest and 9th-windiest month. For the whole year in context, see Diễn Thành's year-round climate.

Daytime high
33°
3rd warmest
Overnight low
26°
9th coldest
Rainfall
115 mm
14 wet days
Daylight
12 h 54 min
5:27 AM – 6:21 PM
Cloud cover
74%
6th clearest
Wind
8 km/h
9th windiest
Solar energy
5.65 kWh/m²
Travel score
3.1
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 32°C in the first days to 34°C by the end.

A typical May day in Diễn Thành reaches about 33°C in the afternoon and slips back to 26°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 37°C. Set against its neighbours, May runs about 3°C warmer than April and about 2°C cooler than June.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13224
23224
33224
43225
53225
63225
73225
83225
93225
103325
113325
123325
133325
143325
153325
163326
173326
183326
193326
203326
213326
223426
233426
243426
253426
263426
273426
283427
293427
303427
313427

How May really feels in Diễn Thành

Once humidity and wind are folded in, May averages 31 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
31
21 feel dangerously hot (≥ 39°C)
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.

Diễn Thành weather by month

How May compares with the rest of the year at a glance. May is the 3rd-warmest and 6th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 15% 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 71%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13664
23664
33664
43763
53763
63763
73664
83664
93664
103565
113565
123466
133367
143268
153268
163070
172971
182872
192773
202575
212575
222476
232377
242278
252278
262179
272179
282179
292080
302080
311981

Chance of precipitation in May

Any precipitation

Diễn Thành gets around 115 mm of rain over 14 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 45% and peaks near 48% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
136
237
338
439
540
640
741
842
943
1043
1144
1244
1345
1445
1546
1646
1746
1847
1947
2047
2147
2247
2348
2448
2548
2648
2748
2848
2948
3047
3147

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 58% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1393850
2293851
3293752
4293653
5283555
6183457
7183457
8173359
9173359
10173359
11173359
12163360
13163360
14163360
15163459
16153460
17153460
18153559
19153559
20143560
21143659
22143659
23133660
24133660
25133660
26133660
27123661
28023662
29023662
30023662
31013762

Wind in May

Winds average 8 km/h in May.

Across May, daily wind ranges from about 8 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 42 min at the start of May to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over May. Sunrise moves from 5:34 AM to 5:24 AM, and sunset from 6:15 PM to 6:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.75:346:15
212.75:346:16
312.75:336:16
412.75:336:16
512.75:326:17
612.85:326:17
712.85:316:17
812.85:316:18
912.85:306:18
1012.85:306:18
1112.85:296:19
1212.85:296:19
1312.95:286:19
1412.95:286:20
1512.95:276:20
1612.95:276:21
1712.95:276:21
1812.95:266:21
1912.95:266:22
2012.95:266:22
2113.05:256:23
2213.05:256:23
2313.05:256:23
2413.05:256:24
2513.05:246:24
2613.05:246:25
2713.05:246:25
2813.05:246:25
2913.05:246:26
3013.05:246:26
3113.05:246:26

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.65 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 — May's 5.65 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.6Bright
55.6Bright
65.6Bright
75.6Bright
85.6Bright
95.6Bright
105.6Bright
115.6Bright
125.6Bright
135.6Bright
145.6Bright
155.6Bright
165.6Bright
175.6Bright
185.6Bright
195.6Bright
205.6Bright
215.7Bright
225.7Bright
235.7Bright
245.7Bright
255.7Bright
265.7Bright
275.7Bright
285.7Bright
295.7Bright
305.8Bright
315.8Bright
Planning a trip in May

Hazard calendar for Diễn Thành

In seasonPeak

In May, 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 May a good time to visit Diễn Thành?

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

3.1
Sightseeing
9th-best month of the year
5.5
Beach & pool
6th-best month of the year

May is a weaker month for outdoor sightseeing in Diễn Thành.

What to pack for Diễn Thành in May

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

In May, Diễn Thành sees daytime highs around 33°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 14 days see rain.

light clothesrain gearsun protection

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

UV index in Diễn Thành in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 11 (very high — sun protection essential). 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 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 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
May 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).