Lai Châu weather in May

In May, Lai Châu sees average daytime highs of 27°C and overnight lows near 20°C, with 222 mm of rain across 24.4 wet days and about 13.1 hours of daylight. It is the 3rd-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 16% 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 18 min by month's end. Set against the rest of the year, May is Lai Châu's 8th-clearest and 5th-windiest month. For the whole year in context, see Lai Châu's year-round climate.

Daytime high
27°
3rd warmest
Overnight low
20°
8th coldest
Rainfall
222 mm
24.4 wet days
Daylight
13 h 06 min
5:30 AM – 6:35 PM
Cloud cover
70%
8th clearest
Wind
4 km/h
5th windiest
Solar energy
4.84 kWh/m²
Travel score
4.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical May day in Lai Châu reaches about 27°C in the afternoon and slips back to 20°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 31°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)
12719
22719
32719
42719
52719
62719
72719
82719
92719
102719
112719
122720
132720
142720
152720
162720
172720
182720
192720
202720
212720
222720
232820
242820
252820
262821
272821
282821
292821
302821
312821

Lai Châu weather by month

How May compares with the rest of the year at a glance. May is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan18° / 10°631010.85.9
Feb20° / 11°539.411.26.4
Mar24° / 14°10613.811.86.5
Apr26° / 17°13618.712.55.4
May27° / 20°22224.413.14.3
Jun28° / 21°32528.513.33.4
Jul27° / 22°38929.513.23.4
Aug28° / 21°37128.712.83.5
Sep27° / 20°20122.212.14.5
Oct25° / 18°961511.56.0
Nov22° / 14°508.710.96.9
Dec19° / 11°497.410.76.5

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 19% 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 (%)
15149
25149
35050
45050
55050
64951
74951
84852
94753
104555
114456
124357
134159
144060
153862
163664
173565
183466
193169
203070
212872
222773
232575
242278
252179
261981
271981
281783
291783
301486
311387

Chance of precipitation in May

Any precipitation

Lai Châu gets around 222 mm of rain over 24.4 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 79% 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 (%)
168
269
369
470
570
671
771
872
973
1074
1175
1276
1377
1477
1578
1679
1780
1881
1982
2082
2183
2284
2385
2486
2586
2687
2788
2889
2989
3090
3191

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 70% of days. Sticky, muggy-or-worse air turns up on roughly 79% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
11633600
21632610
31630630
41629631
51528651
61526671
71525681
81524682
91523692
101421722
111420723
121419724
131418725
141417735
151416727
161415728
171314739
1813137310
1913127311
2013127212
2113117213
2212107314
2302107315
240297316
250297118
260287119
270187120
280177121
290167122
300167023
310157024

Wind in May

Winds average 4 km/h in May.

Across May, daily wind ranges from about 3 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
213calm
223calm
233calm
243calm
253calm
263calm
273calm
283calm
293calm
303calm
313calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 48 min at the start of May to 13 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 30 minutes over May. Sunrise moves from 5:39 AM to 5:26 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)
112.85:396:28
212.85:386:28
312.95:386:29
412.95:376:29
512.95:366:30
612.95:366:30
712.95:356:30
812.95:346:31
913.05:346:31
1013.05:336:32
1113.05:336:32
1213.05:326:33
1313.05:326:33
1413.05:316:34
1513.15:316:34
1613.15:306:35
1713.15:306:35
1813.15:296:35
1913.15:296:36
2013.15:296:36
2113.15:286:37
2213.25:286:37
2313.25:286:38
2413.25:276:38
2513.25:276:39
2613.25:276:39
2713.25:276:40
2813.25:266:40
2913.25:266:40
3013.25:266:41
3113.35:266:41

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.84 kWh/m².

For context, solar energy here swings from a low near 2.66 kWh/m² to a high of 4.99 kWh/m² in April across the year — May's 4.84 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.1Bright
25.1Bright
35.1Bright
45.1Bright
55.1Bright
65.1Bright
75.1Bright
85.1Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
134.9Bright
144.9Bright
154.9Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.7Bright
214.7Bright
224.7Bright
234.6Bright
244.6Bright
254.6Bright
264.6Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
314.5Bright
Planning a trip in May

Hazard calendar for Lai Châu

In seasonPeak

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

Lai Châu'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 Lai Châu?

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

4.3
Sightseeing
9th-best month of the year
4.5
Beach & pool
6th-best month of the year

May is a reasonable time to visit Lai Châu for sightseeing.

What to pack for Lai Châu in May

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

In May, Lai Châu sees daytime highs around 27°C and nights near 20°C. Pack light clothes and rain gear. Worth having: sun protection. About 24 days see rain.

light clothesrain gearsun protection

UV index in Lai Châu 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 Lai Châu peaks around June 19 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highExtremeVery highHighJun 19UV 14Dec 19UV 5
UV index (midday)Level
Jan7High
Feb9Very high
Mar11Extreme
Apr9Very high
May11Extreme
Jun14Extreme
Jul13Extreme
Aug12Extreme
Sep10Very high
Oct9Very high
Nov8Very high
Dec5High

Air quality in Lai Châu 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 Lai Châu is worst in April — around 70 µg/m³ PM2.5 (unhealthy), about 5.0× the cleanest month (July, 14 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorUnhealthyModerateApr 1367 µg/m³Jul 1814 µg/m³
PM2.5 (µg/m³)Level
Jan25Moderate
Feb33Moderate
Mar54Poor
Apr70Unhealthy
May28Moderate
Jun15Moderate
Jul14Moderate
Aug15Moderate
Sep18Moderate
Oct22Moderate
Nov23Moderate
Dec25Moderate
Location & terrain

Where is Lai Châu?

Lai Châu sits at 22.4°N, 103.5°E, 919 m above sea level, in Vietnam. The nearest listed city is Sapa, 40 km away.

Thị Trấn Thuận ChâuÍt OngDien Bien PhuSơn La

Topography around Lai Châu

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

Within 3 km, the terrain around Lai Châu has significant variations in elevation — a maximum elevation change of 544 m around an average of 1,001 m above sea level; within 16 km, extreme variations in elevation — a maximum elevation change of 2,836 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,035 m.

The land around Lai Châu is covered by trees (43%) and grassland (32%) within 3 km, trees (74%) within 16 km, and trees (85%) within 80 km.

3 km
544 m
16 km
2,836 m
80 km
3,035 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Sapa 40 km · Lào Cai 54 km · Mường Lay 55 km · Thị Trấn Phố Lu 75 km · Thị Trấn Thuận Châu 109 km · Ít Ong 114 km · Dien Bien Phu 121 km · Sơn La 128 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 Lai Châu (22.3964°, 103.4582°, elevation 919 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).