Dien Bien Phu weather in May

In May, Dien Bien Phu sees average daytime highs of 29°C and overnight lows near 21°C, with 195 mm of rain across 22.2 wet days and about 13 hours of daylight. It is the 1st-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 15% of the time in May, and the air most often feels muggy.

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 Dien Bien Phu's 8th-clearest and 5th-windiest month. For the whole year in context, see Dien Bien Phu's year-round climate.

Daytime high
29°
1st warmest
Overnight low
21°
8th coldest
Rainfall
195 mm
22.2 wet days
Daylight
13 hours
5:34 AM – 6:35 PM
Cloud cover
73%
8th clearest
Wind
5 km/h
5th windiest
Solar energy
5.06 kWh/m²
Travel score
3.8
out of 10

Dien Bien Phu is city in Điện Biên, Vietnam.

Density
1,317/km²
people per km²
Founded
1992

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical May day in Dien Bien Phu reaches about 29°C in the afternoon and slips back to 21°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 33°C. Set against its neighbours, May runs on par with April and on par with June.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12920
22920
32920
42920
52920
62920
72920
82920
92920
102921
112921
122921
132921
142921
152921
162921
172921
182921
192921
202921
212921
222921
232921
242921
252921
262921
272922
282922
292922
302922
312922

Dien Bien Phu weather by month

How May compares with the rest of the year at a glance. May is the 1st-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan22° / 11°35510.87.5
Feb24° / 12°254.811.37.9
Mar27° / 16°558.611.86.9
Apr29° / 19°11515.412.55.1
May29° / 21°19522.2133.8
Jun28° / 22°32327.313.33.2
Jul28° / 22°40328.913.23.4
Aug28° / 22°36828.312.73.4
Sep28° / 21°19921.512.14.4
Oct26° / 19°7211.511.56.3
Nov24° / 15°335.5117.7
Dec22° / 12°294.510.77.6

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 70%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14951
24852
34852
44753
54654
64555
74456
84357
94258
104060
113862
123763
133664
143466
153268
163070
172971
182872
192575
202476
212377
222278
232080
241882
251684
261585
271585
281486
291288
301189
311090

Chance of precipitation in May

Any precipitation

Dien Bien Phu gets around 195 mm of rain over 22.2 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 72% and peaks near 87% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202531
Rain chance (%)
160
260
361
462
562
663
764
865
965
1066
1167
1268
1369
1470
1571
1672
1773
1873
1974
2075
2176
2277
2378
2479
2580
2681
2782
2883
2985
3086
3187

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the muggy band about 52% of days. Sticky, muggy-or-worse air turns up on roughly 90% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1220708
2219709
32177110
42167111
53156913
63146914
73136816
83126718
93116620
103106522
113106324
12396226
13386029
14385831
15375634
16375436
17365239
18365041
19254943
20254746
21254548
22244351
23244153
24143956
25143758
26133561
27133462
28123265
29023068
30022870
31022771

Wind in May

Winds average 5 km/h in May.

Across May, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

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 5:42 AM to 5:29 AM, and sunset from 6:28 PM to 6:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:426:28
212.85:416:29
312.85:416:29
412.85:406:30
512.85:396:30
612.95:396:30
712.95:386:31
812.95:386:31
912.95:376:32
1012.95:366:32
1112.95:366:32
1213.05:356:33
1313.05:356:33
1413.05:356:34
1513.05:346:34
1613.05:346:35
1713.05:336:35
1813.05:336:36
1913.15:326:36
2013.15:326:36
2113.15:326:37
2213.15:316:37
2313.15:316:38
2413.15:316:38
2513.15:316:39
2613.15:306:39
2713.25:306:39
2813.25:306:40
2913.25:306:40
3013.25:306:41
3113.25:296:41

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.06 kWh/m².

For context, solar energy here swings from a low near 3.4 kWh/m² to a high of 5.44 kWh/m² in April across the year — May's 5.06 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.4Bright
55.4Bright
65.3Bright
75.3Bright
85.3Bright
95.3Bright
105.3Bright
115.2Bright
125.2Bright
135.2Bright
145.1Bright
155.1Bright
165.1Bright
175.0Bright
185.0Bright
195.0Bright
204.9Bright
214.9Bright
224.9Bright
234.8Bright
244.8Bright
254.8Bright
264.8Bright
274.7Bright
284.7Bright
294.7Bright
304.6Bright
314.6Bright
Planning a trip in May

Hazard calendar for Dien Bien Phu

In seasonPeak

In May, Dien Bien Phu sits inside its monsoon season. The full year is below, with each hazard's peak months called out.

Dien Bien Phu's monsoon runs May–September, when most of the year's rain falls.

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

Is May a good time to visit Dien Bien Phu?

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

3.8
Sightseeing
9th-best month of the year
5.0
Beach & pool
8th-best month of the year

May is a weaker month for outdoor sightseeing in Dien Bien Phu.

What to pack for Dien Bien Phu in May

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

In May, Dien Bien Phu sees daytime highs around 29°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 22 days see rain.

light clothesrain gearsun protection

UV index in Dien Bien Phu 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 Dien Bien Phu peaks around August 12 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 highExtremeVery highHighAug 12UV 14Dec 19UV 6
UV index (midday)Level
Jan7Very high
Feb9Very high
Mar11Extreme
Apr9Very high
May10Extreme
Jun14Extreme
Jul13Extreme
Aug14Extreme
Sep10Very high
Oct9Very high
Nov8Very high
Dec6High

Air quality in Dien Bien Phu 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 Dien Bien Phu is worst in April — around 303 µg/m³ PM2.5 (very unhealthy), about 32.6× the cleanest month (August, 9 µg/m³).

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

0306090120150180210240270300JanFebMarAprMayJunJulAugSepOctNovDecModerateUnhealthyVery unhealthyUnhealthyGoodModerateApr 15276 µg/m³Aug 109 µg/m³
PM2.5 (µg/m³)Level
Jan20Moderate
Feb37Poor
Mar107Unhealthy
Apr303Very unhealthy
May53Poor
Jun11Good
Jul10Good
Aug9Good
Sep11Good
Oct15Moderate
Nov17Moderate
Dec19Moderate
Location & terrain

Where is Dien Bien Phu?

Dien Bien Phu sits at 21.4°N, 103.0°E, 485 m above sea level, in Vietnam. The nearest listed city is Mường Lay, 69 km away.

Sơn LaNong KhiawÍt OngLai ChâuMuang XaySapa

Topography around Dien Bien Phu

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Dien Bien Phu.

Within 3 km, the terrain around Dien Bien Phu has significant variations in elevation — a maximum elevation change of 255 m around an average of 505 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,307 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,010 m.

The land around Dien Bien Phu is covered by trees (36%), cropland (30%) and artificial surfaces (24%) within 3 km, trees (62%) and grassland (23%) within 16 km, and trees (79%) within 80 km.

3 km
255 m
16 km
1,307 m
80 km
2,010 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Mường Lay 69 km · Thị Trấn Thuận Châu 69 km · Sơn La 93 km · Nong Khiaw 100 km · Ít Ong 105 km · Lai Châu 121 km · Muang Xay 133 km · Sapa 136 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 Dien Bien Phu (21.386°, 103.023°, elevation 485 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. 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).