Mường Lay weather in May

In May, Mường Lay sees average daytime highs of 29°C and overnight lows near 21°C, with 328 mm of rain across 25.2 wet days and about 13 hours of daylight. It is the 1st-warmest and 4th-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 oppressive.

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 Mường Lay's 9th-clearest and 8th-windiest month. For the whole year in context, see Mường Lay's year-round climate.

Daytime high
29°
1st warmest
Overnight low
21°
8th coldest
Rainfall
328 mm
25.2 wet days
Daylight
13 hours
5:32 AM – 6:35 PM
Cloud cover
72%
9th clearest
Wind
3 km/h
8th windiest
Solar energy
4.87 kWh/m²
Travel score
3.5
out of 10

Mường Lay is old town of Dien Bien province, Vietnam.

Density
179/km²
people per km²
Founded
1971

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 Mường Lay 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 about 1°C warmer than April and on par with June.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12920
22920
32920
42920
52920
62921
72921
82921
92921
102921
112921
122921
132921
142921
152921
162921
172921
182921
192921
202922
212922
222922
232922
242922
252922
262922
272922
282922
292922
302922
312922

How May really feels in Mường Lay

Once humidity and wind are folded in, May averages 13 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
13
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.

Mường Lay weather by month

How May compares with the rest of the year at a glance. May is the 1st-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan21° / 12°59810.86.8
Feb23° / 12°548.311.27.1
Mar26° / 15°12313.111.86.3
Apr28° / 19°21919.512.54.7
May29° / 21°32825.2133.5
Jun29° / 23°45528.313.32.9
Jul29° / 23°45329.413.23.0
Aug29° / 23°36426.912.83.2
Sep29° / 22°18719.712.14.2
Oct27° / 20°8613.711.55.9
Nov24° / 16°55810.97.2
Dec21° / 13°476.210.77.1

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 16% 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 (%)
14753
24654
34654
44654
54555
64456
74357
84357
94159
104060
113862
123763
133664
143466
153268
163169
173169
182971
192773
202674
212476
222278
232179
242080
251981
261684
271585
281585
291486
301387
311288

Chance of precipitation in May

Any precipitation

Mường Lay gets around 328 mm of rain over 25.2 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 82% and peaks near 91% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202531
Rain chance (%)
174
274
375
475
575
675
776
876
976
1077
1178
1278
1379
1480
1581
1681
1782
1883
1984
2084
2185
2285
2386
2487
2587
2688
2789
2889
2990
3090
3191

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the oppressive band about 68% of days. Sticky, muggy-or-worse air turns up on roughly 95% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
11753390
21751410
31749430
41747450
51745480
61742500
71740520
81737550
91735570
101633600
111631620
121629640
131627660
141626661
151624681
161523701
171522711
181521721
190419761
200418771
210417781
220316801
230315811
240214831
250213841
260212851
270111871
280110881
29019891
30018901
31008911

Wind in May

Winds average 3 km/h in May.

Across May, daily wind ranges from about 2 km/h on the calmest days to 3 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
13calm
23calm
33calm
43calm
53calm
63calm
73calm
83calm
93calm
103calm
113calm
123calm
133calm
143calm
153calm
163calm
173calm
183calm
193calm
203calm
213calm
223calm
233calm
243calm
253calm
263calm
273calm
283calm
292calm
302calm
312calm

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

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:416:29
212.85:406:29
312.85:396:29
412.95:396:30
512.95:386:30
612.95:376:31
712.95:376:31
812.95:366:32
912.95:366:32
1013.05:356:33
1113.05:356:33
1213.05:346:33
1313.05:346:34
1413.05:336:34
1513.05:336:35
1613.05:326:35
1713.15:326:36
1813.15:316:36
1913.15:316:37
2013.15:316:37
2113.15:306:37
2213.15:306:38
2313.15:306:38
2413.25:296:39
2513.25:296:39
2613.25:296:40
2713.25:296:40
2813.25:286:41
2913.25:286:41
3013.25:286:41
3113.25:286:42

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.87 kWh/m².

For context, solar energy here swings from a low near 3.09 kWh/m² to a high of 5.2 kWh/m² in April across the year — May's 4.87 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.2Bright
85.1Bright
95.1Bright
105.1Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
154.9Bright
164.9Bright
174.8Bright
184.8Bright
194.8Bright
204.7Bright
214.7Bright
224.7Bright
234.6Bright
244.6Bright
254.6Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.4Bright
314.4Bright
Planning a trip in May

Hazard calendar for Mường Lay

In seasonPeak

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

Mường Lay's monsoon runs April–August, 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 Mường Lay?

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

3.5
Sightseeing
9th-best month of the year
4.5
Beach & pool
8th-best month of the year

May is a weaker month for outdoor sightseeing in Mường Lay.

What to pack for Mường Lay in May

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

In May, Mường Lay sees daytime highs around 29°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 25 days see rain.

light clothesrain gearsun protection

UV index in Mường Lay 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 Mường Lay peaks around June 19 at about 13 (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 highVery highExtremeVery highHighJun 19UV 13Dec 19UV 6
UV index (midday)Level
Jan7High
Feb9Very high
Mar11Extreme
Apr9Very high
May11Extreme
Jun14Extreme
Jul13Extreme
Aug12Extreme
Sep10Very high
Oct9Very high
Nov8Very high
Dec6High

Air quality in Mường Lay 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 Mường Lay is worst in April — around 99 µg/m³ PM2.5 (unhealthy), about 8.1× the cleanest month (July, 12 µg/m³).

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

0306090120JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorUnhealthyModerateApr 1395 µg/m³Jul 2212 µg/m³
PM2.5 (µg/m³)Level
Jan31Moderate
Feb41Poor
Mar73Unhealthy
Apr99Unhealthy
May32Moderate
Jun14Moderate
Jul12Moderate
Aug13Moderate
Sep17Moderate
Oct23Moderate
Nov26Moderate
Dec30Moderate
Location & terrain

Where is Mường Lay?

Mường Lay sits at 22.0°N, 103.1°E, 496 m above sea level, in Vietnam. The nearest listed city is Lai Châu, 55 km away.

Lào CaiÍt OngSơn LaThị Trấn Phố Lu

Topography around Mường Lay

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

Within 3 km, the terrain around Mường Lay has large variations in elevation — a maximum elevation change of 987 m around an average of 501 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,867 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,950 m.

The land around Mường Lay is covered by trees (78%) within 3 km, trees (80%) within 16 km, and trees (80%) within 80 km.

3 km
987 m
16 km
1,867 m
80 km
2,950 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Lai Châu 55 km · Dien Bien Phu 69 km · Sapa 82 km · Thị Trấn Thuận Châu 85 km · Lào Cai 102 km · Ít Ong 107 km · Sơn La 111 km · Thị Trấn Phố Lu 114 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 Mường Lay (22°, 103.1333°, elevation 496 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).