The climate of Laos is tropical in most of the plains, while it's subtropical in the far north and in the mountains, besides it's governed by the monsoons: the winter monsoon, which brings good weather and a bit of cool at night from November to February, and the summer monsoon, which brings humidity and rainfall from May to the beginning or the middle of October. However, the monsoons are quite irregular: they do not always arrive in the same period, and they don't always have the same intensity.
The period from March to May, before the rains, is the hottest of the year, and it is still dry, but with some thunderstorms in the afternoon; the summer months are less hot, with highs around 30/32 °C (86/90 °F), but with higher moisture. April is the hottest month, with average highs about 35 °C (95 °F), but with peaks of 40/42 °C (104/108 °F) in the centre-south, and even 45 °C (113 °F) in the north, which has a greater continentality. In May, the temperature begins to decrease in the south, while in the north, where the monsoon arrives later, it's still very hot, especially in the first part.
In Laos, the rainfall amount is normally between 1,200 and 2,200 millimetres (47 and 87 inches) per year in the plains, and may exceed 3,000 mm (118 in) in the most exposed mountain slopes. The rainiest months are usually August and September, which correspond to the final period of the monsoon, also because of typhoons (see below), which bring an additional amount of rain.

Index


The north


Luang Prabang

During winter, nights are cool in the north, around 14/15 °C (57/59 °F) from December to February in Luang Prabang, but with peaks near the freezing point; highs are around 27/28 °C (81/82 °F) in December and January, while as early as in February they reach 31 °C (88 °F). Sometimes during the day it can get hot even in winter.
Here are the average temperatures of Luang Prabang.
Luang Prabang - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)141518212324242423211814
Max (°C)283134353433323132312927
Min (°F)575964707375757573706457
Max (°F)828893959391908890888481

In Luang Prabang, 1,250 mm (49 in) of rain per year fall, so we are in one of the least rainy areas.
Luang Prabang - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)1515359515017522522516510530151250
Prec.(in)0.60.61.43.75.96.98.98.96.54.11.20.649.2
Days13491515192014941114

In the north, the amount of sunshine is not very good, because even in the dry season the sky is often cloudy; in the extreme north, in winter there's often a dull weather and there can be some drizzle; sometimes this can also happen in Luang Prabang and in the rest of the north. During the period of the summer monsoon, cloudiness prevails throughout the country, although sometimes the sun can come out. Here are the sunshine hours in Luang Prabang.
Luang Prabang - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours676764456666

Bounneua

Laos, a landlocked country, is mountainous and covered with forests, and it's home to several parks and protected areas. In general, the climate becomes milder with increasing altitude, but it becomes even more rainy, with the first pre-monsoon showers more frequent than in the plains, and definitely abundant rains in the monsoon period.
Here are the mean temperatures of Boun Neua, located in the far north, at 900 metres (3,000 feet) above sea level.
Bounneua - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)101012161921212019171410
Max (°C)222527292928282828262422
Min (°F)505054616670706866635750
Max (°F)727781848482828282797572

At high altitudes, it can get cold even during the day in the winter months, especially in the north. The highest peak is Phou Bia, 2,819 metres (9,249 feet) high.

Mountains of Laos

The centre-south



In the centre-south (see Vientiane, Savannakhet), the winter temperatures are slightly higher, and outbreaks of cold air are less frequent and less intense.

Vientiane

Here are the average temperatures of the capital Vientiane.
Vientiane - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)161922242525252524231917
Max (°C)283033343332313131313028
Min (°F)616672757777777775736663
Max (°F)828691939190888888888682

In Vientiane, 1,600 mm (63 in) of rain per year fall; the rains are abundant from May to September, while they are rare from November to March. Here is the average precipitation.
Vientiane - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)8133585245280270335295801031661
Prec.(in)0.30.51.43.39.61110.613.211.63.10.40.165.4
Days12481518202117921118

In the centre-south, the amount of sunshine is good in the dry season, from November to April.
Vientiane - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours887875545888

Pakxe

In the far south (see Pakxe), winter is even warmer, actually it's quite hot, so that highs are normally around 30/31 °C (86/88 °F) even in December and January.
Pakxe - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)182124252525242424232119
Max (°C)313335353331313030313130
Min (°F)647075777777757575737066
Max (°F)889195959188888686888886

In Pakxe, the rains are abundant, since they amount to 2,000 mm (80 in) per year; from June to September, they exceed even 300 mm (12 in) per month. However, here too, from November to March it rains very rarely.
In the dry period, in Pakxe the sun shines even more often than in Vientiane and in the center of the country.
Pakxe - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours999775545688

Typhoons

Laos can be reached by typhoons, the tropical cyclones of south-east Asia, which come from the South China Sea, and affect more directly the coast of Vietnam, though they can bring wind and heavy rainfall also in Laos. Typically, typhoons pass from May 20 to December 15; the north is hit more often than the south.
More rarely, the north-west may be affected by the remains of cyclones coming from the Bay of Bengal, which may also pass from the second half of April onwards, as happened with Typhoon Nargis in early May 2008.
Tropical cyclones, as well as waves of bad weather during the monsoon season, may cause flooding, as well as the overflowing of the great river that runs through the country from north to south, the Mekong.

When to go



The best time to visit Laos is from November to February, being the coolest part of the dry season. In November, however, typhoons or tropical storms may still affect the country, and sometimes even in the first half of December. In February, usually the temperature begins to rise, so that it can exceed 35 °C (95 °F); therefore the best time is from mid-December to late January, even though sometimes it can get hot even in January, but the humidity is not high and nights remain cool. It is worth while to recall that in winter it can get cold at night across the country, so that minimum temperatures can drop below 10 °C (50 °F), but especially in the north, where it can drop in some cases even to the freezing point.
In March and April, and also in May until the arrival of the monsoon, it's uncomfortably hot in the lowlands, while in the mountains the heat it's more bearable. The weather is still good, although during the afternoon there may be some showers and thunderstorms.
During the rainy season, from May to September, the heat is sweltering, at least in the lowlands, the sky is often cloudy, and sometimes torrential rains can make travelling difficult; in the brief periods of good weather, which last a few days, the heat returns to be intense.

What to pack



In winter: in the north (see Luang Prabang), light clothes for the day, a jacket and a sweater for the evening, raincoat for the drizzle; in the northern cities above 1,000 metres (3,300 feet), spring/autumn clothes, a warm jacket and a sweater for the evening. For the south-central plains (Vientiane, Savannakhet, Pakxe), light clothing, a light sweatshirt for the evening, possibly a light jacket or a sweater for cooler evenings. For the highest peaks, warm clothes, down jacket, hat, gloves.
In summer: all over the country, at low altitude, lightweight clothing of natural fibres, light raincoat or umbrella, a light sweater for the evening; above 1,000 metres (3,300 feet) you can add a sweatshirt and a light jacket; for the highest peaks, warm clothes, sweater, raincoat, hiking shoes.
Before entering pagodas, it is customary to remove shoes, dress neatly and cover a little.