Best time to visit Vietnam

Best months: February, January and March
Year: 2001-2020
Spread between cities: 31 (in December)

The answer for Vietnam is computed across 3 measured cities, and there February, January and March come out best on the twenty year normals for 2001-2020. That is an average of real places rather than a figure for the country as a whole, because no such figure exists.

All 3 cities put February among their own best months, so this is one of the rare countries where the answer holds wherever you go.

The widest disagreement is in December, where the measured cities sit 31 points apart: Hanoi scores best and Da Nang worst in the same month. A single best time for Vietnam hides that gap, and for part of the country it would be the wrong answer.

The numbers behind that: February averages 22.6 degrees across the measured cities, from Hanoi at 18.2 to Ho Chi Minh City at 28, and brings about 18 mm of rain.

The months to avoid are August and September, and what decides it is the rain.

Each month is scored on its mean temperature, its rainfall and its humidity, taken from the provider twenty year normals for 2001-2020. The cities are Ho Chi Minh City, Hanoi and Da Nang. The comfort bands and the penalties are fixed and published, so a reader who disagrees with the ranking can see exactly which part of it they disagree with.

The source publishes a monthly mean and, separately, the highest and lowest values it recorded in twenty years. Those extremes are not a typical afternoon or a typical night, so nothing here is quoted as one. This page does not say what the daytime high usually is, because this source cannot say it.

Normals are not a forecast. They describe what twenty years averaged to, and any single year can sit well outside them. They also describe a model grid cell of roughly fifty kilometres rather than a weather station, so a coastal city and the sea beside it share one figure.