All countries of Southeast Asia are subject to monsoon climate. Laos and Cambodia have similar climate to Southern Vietnam where it is warm all year round. Only the North of Vietnam experiences a winter when temperature may drop to 10 ° C. North, Central and South Vietnam have significantly different climatic conditions.
Vietnam Climate:
With its slim shape and a long coastline of over 3000 km, Vietnamese climate is varied significantly from North, Central to South.
Temperatures: While in the South, it is hot all year, the North does have a "winter", when temperature is around 10 ° C.
Rain: In Northern Vietnam (Hanoi), the rainy season lasts about five months (mid-May to September). In other two regions, rainfall picks up in October and November. In the central region (Hue, Hoi An), rain may last for days while in the South it is mainly short downpour.
Generally, there is really no bad time to visit Vietnam. Everything ultimately depends on your preferences to travel with cooler or warmer weather.
Cambodia Climate:
Like any tropical country, Cambodia has two seasons: winter (November-March) and summer (May to October). The first is relatively dry (with a temperature around 25-30 ° C) and the second is very hot (up to 35 ° C) and humid (short downpours late in the day and floods are commonly expected).
November to March is the best time to go.
Laos Climate:
Like South Vietnam, Laos is subject to tropical and subtropical climate with two main seasons:
The dry season from October to April: Average temperature is 21°C in November and February, and 25 ° C in October and March. From mid-March to late April, however, temperatures may climb to 40 ° C in the plains.
The rainy season lasts from May to September. Warm and moist monsoon, which flows first south of the country extensively then rising to the north. It may be difficult to travel in the country during these months. The temperature approaches 30 ° C in Vientiane and rainfall reaches close to 300 mm. To visit Laos in this season, the north is more appropriate.
The most pleasant time to visit Laos is the months of October, November, February and March, when the temperature is adequate (averagely 25°C). The sky is blue and, importantly: this is the period of most Lao festivals!
Months marked in blue areas representing the best times to visit the country. The least favorable months are colored in grey.
For beach lovers, please rest assured that all stunning stretches in southern half of Vietnam enjoy year round sunshine.