Vietnam's climate varies significantly from north to south given its elongated geography. The north (Hanoi) has four distinct seasons including a genuinely cold, damp winter (temperatures can drop to 10-15°C) and a hot, humid summer; the central region (Da Nang, Hue) has a hot dry season and a wet season with typhoon risk (roughly September-November); the south (Ho Chi Minh City, Mekong Delta) has a consistent tropical climate with just two seasons — hot/dry (roughly November-April) and hot/wet (roughly May-October) — with minimal temperature variation year-round.
Typhoon season (roughly September-November) hits central Vietnam hardest and can disrupt flights, flooding, and infrastructure for days at a time — worth factoring into travel and business planning if you're based in or frequently visiting Da Nang, Hue, or nearby coastal areas during that window.
Key Facts
Northern Vietnam (Hanoi): four seasons — cold, damp winter (Dec-Feb, 10-18°C), a pleasant spring, a very hot/humid summer (Jun-Aug, regularly 30-38°C with high humidity), and a mild autumn.
Central Vietnam (Da Nang, Hue, Hoi An): hot, mostly dry season (roughly Feb-Aug) and a wet season with peak typhoon risk (roughly Sep-Nov) bringing heavy rainfall and occasional flooding.
Southern Vietnam (Ho Chi Minh City, Mekong Delta): consistently tropical, minimal seasonal temperature swing (typically 25-34°C year-round), with a dry season (Nov-Apr) and a wet season (May-Oct) marked by frequent but often short, intense afternoon downpours.
Humidity is high nationwide for much of the year, a major factor in daily comfort and driving widespread air-conditioning use (and associated electricity costs).
Typhoon season (roughly Jun-Nov, peaking Sep-Nov) primarily affects the central and northern coasts, occasionally disrupting flights and causing localized flooding.
Best-weather travel/relocation windows are generally considered: Feb-Apr for the north (mild, less rain), Feb-Aug for central Vietnam (dry season), and Nov-Apr for the south (dry, less humid).
Timelines
Northern Vietnam cold season: December - February
Central Vietnam typhoon/wet season: September - November (peak risk)
Southern Vietnam wet season: May - October
Common Mistakes
Assuming Vietnam has one uniform tropical climate — Hanoi's winter is genuinely cold and requires warm clothing, unlike Ho Chi Minh City.
Scheduling a move or major travel to central Vietnam during typhoon season (Sep-Nov) without contingency plans for flight/flood disruption.
Underestimating humidity's impact on daily comfort and electricity costs (air conditioning) even in the 'dry' season.
Not packing/preparing for the north's cold, damp winter when relocating there expecting Southeast Asian tropical warmth year-round.