Vietnam spans several climatic zones, resulting in substantial weather condition variations between the north and the south. Average temperatures year-round range from 20 to 35 degrees Celsius. There is no particularly good or bad time to visit Vietnam.

In Southern Vietnam tropical conditions prevail, and there are two seasons – the wet season lasts from May to November and the dry season from December to April. The wet is characterised by high humidity levels and a refreshing afternoon downpour. Humidity in the south during the months of June and July ranges between 75% and 85%. The hottest months are from March to May.

Central Vietnam is usually dry from May to October and wet from December to February. October and November occasionally see unstable weather conditions and flooding.

Northern Vietnam also experiences two seasons, though conditions can change dramatically throughout the day. The winter months from November to April are usually cold and humid. The months of December and January can be particularly cool with temperatures as low as 8 degrees Celsius. Temperatures can drop to 0 degrees Celsius in Sapa (in the highlands near the Chinese border) in winter. Summer, from May to October, can be quite hot and wet with regular downpours and occasional typhoons. The hottest months are July and August.