Lào Cai weather in May

In May, Lào Cai sees average daytime highs of 29°C and overnight lows near 22°C, with 200 mm of rain across 19.7 wet days and about 13.1 hours of daylight. It is the 4th-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 19% 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 18 min by month's end. Set against the rest of the year, May is Lào Cai's 8th-clearest and 6th-windiest month. For the whole year in context, see Lào Cai's year-round climate.

Daytime high
29°
4th warmest
Overnight low
22°
8th coldest
Rainfall
200 mm
19.7 wet days
Daylight
13 h 06 min
5:28 AM – 6:33 PM
Cloud cover
70%
8th clearest
Wind
4 km/h
6th windiest
Solar energy
4.86 kWh/m²
Travel score
4.1
out of 10

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 Lào Cai reaches about 29°C in the afternoon and slips back to 22°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 2°C warmer than April and about 1°C cooler than June.

15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12920
22921
32921
42921
52921
62921
72921
82921
92921
102921
112921
122921
132922
142922
152922
162922
172922
182922
192922
202922
212922
222922
232922
242922
253022
263023
273023
283023
293023
303023
313023

How May really feels in Lào Cai

Once humidity and wind are folded in, May averages 9 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
9
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.

Lào Cai weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan18° / 11°9618.110.84.7
Feb20° / 12°871711.25.0
Mar24° / 15°1261911.85.5
Apr27° / 19°12917.612.55.2
May29° / 22°20019.713.14.1
Jun30° / 24°2422213.43.3
Jul30° / 24°26123.213.23.4
Aug30° / 23°26822.412.83.6
Sep28° / 22°16518.212.14.6
Oct26° / 19°11816.611.55.7
Nov23° / 15°8813.810.96.1
Dec19° / 12°9214.110.65.5

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 66%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14753
24753
34753
44654
54654
64555
74456
84555
94357
104357
114258
124060
134060
143862
153862
163664
173664
183466
193268
203169
213070
222872
232773
242575
252377
262377
272179
282179
291882
301783
311684

Chance of precipitation in May

Any precipitation

Lào Cai gets around 200 mm of rain over 19.7 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 64% and peaks near 70% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
160
260
360
460
560
661
761
861
961
1061
1162
1262
1362
1462
1563
1663
1763
1864
1964
2064
2165
2265
2366
2466
2567
2668
2768
2869
2969
3070
3170

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 52% of days. Sticky, muggy-or-worse air turns up on roughly 89% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
14146022
23145924
33135925
43135727
53125629
63125431
73115333
83105136
94104938
10494740
11494542
12494344
13484146
14484049
15373852
16373654
17373555
18363457
19363358
20263161
21263062
22252964
23152866
24152668
25152569
26142471
27142273
28042175
29031978
30031879
31031780

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
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
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 5:37 AM to 5:24 AM, and sunset from 6:26 PM to 6:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:376:26
212.85:366:26
312.95:356:27
412.95:356:27
512.95:346:28
612.95:336:28
712.95:336:29
812.95:326:29
913.05:326:29
1013.05:316:30
1113.05:316:30
1213.05:306:31
1313.05:306:31
1413.05:296:32
1513.15:296:32
1613.15:286:33
1713.15:286:33
1813.15:276:34
1913.15:276:34
2013.15:266:34
2113.15:266:35
2213.25:266:35
2313.25:256:36
2413.25:256:36
2513.25:256:37
2613.25:256:37
2713.25:246:38
2813.25:246:38
2913.25:246:39
3013.35:246:39
3113.35:246:39

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.86 kWh/m².

For context, solar energy here swings from a low near 2.56 kWh/m² to a high of 4.91 kWh/m² in April across the year — May's 4.86 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
135.0Bright
144.9Bright
154.9Bright
164.9Bright
174.8Bright
184.8Bright
194.8Bright
204.8Bright
214.8Bright
224.7Bright
234.7Bright
244.7Bright
254.7Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.6Bright
314.6Bright
Planning a trip in May

Hazard calendar for Lào Cai

In seasonPeak

In May, Lào Cai sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Lào Cai's rainy season runs March–September, when most of the year's rain falls.

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

Is May a good time to visit Lào Cai?

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

4.1
Sightseeing
9th-best month of the year
5.3
Beach & pool
4th-best month of the year

May is a reasonable time to visit Lào Cai for sightseeing.

What to pack for Lào Cai in May

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

In May, Lào Cai sees daytime highs around 29°C and nights near 22°C. Pack light clothes and rain gear. Worth having: sun protection. About 20 days see rain.

light clothesrain gearsun protection

UV index in Lào Cai 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 Lào Cai peaks around June 21 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highVery highExtremeVery highHighJun 21UV 13Dec 18UV 5
UV index (midday)Level
Jan6High
Feb8Very high
Mar11Extreme
Apr8Very high
May10Very high
Jun14Extreme
Jul13Extreme
Aug12Extreme
Sep10Very high
Oct8Very high
Nov7High
Dec5High

Air quality in Lào Cai 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 Lào Cai is worst in March — around 49 µg/m³ PM2.5 (poor), about 2.8× the cleanest month (July, 17 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModeratePoorMar 2349 µg/m³Jul 1817 µg/m³
PM2.5 (µg/m³)Level
Jan36Poor
Feb40Poor
Mar49Poor
Apr48Poor
May30Moderate
Jun19Moderate
Jul17Moderate
Aug18Moderate
Sep23Moderate
Oct28Moderate
Nov33Moderate
Dec36Poor
Location & terrain

Where is Lào Cai?

Lào Cai sits at 22.5°N, 104.0°E, 86 m above sea level, in Vietnam. The nearest listed city is Sapa, 21 km away.

Bắc QuangMường LayÍt OngHà Giang

Topography around Lào Cai

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

Within 3 km, the terrain around Lào Cai has significant variations in elevation — a maximum elevation change of 298 m around an average of 141 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,148 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,050 m.

The land around Lào Cai is covered by trees (65%) and artificial surfaces (26%) within 3 km, trees (90%) within 16 km, and trees (85%) within 80 km.

3 km
298 m
16 km
2,148 m
80 km
3,050 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Sapa 21 km · Thị Trấn Phố Lu 29 km · Lai Châu 54 km · Thị Trấn Việt Quang 86 km · Bắc Quang 92 km · Mường Lay 102 km · Ít Ong 108 km · Hà Giang 111 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 Lào Cai (22.4856°, 103.9707°, elevation 86 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).