Best time to visit Portugal

Best months: July, August and June
Year: 2001-2020
Spread between cities: 27 (in January)

The answer for Portugal is computed across 3 measured cities, and there July, August and June 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 July 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 January, where the measured cities sit 27 points apart: Faro scores best and Porto worst in the same month. A single best time for Portugal hides that gap, and for part of the country it would be the wrong answer.

The numbers behind that: July averages 21.1 degrees across the measured cities, from Lisbon at 19.9 to Faro at 23.4, and brings about 6 mm of rain.

The months to avoid are January and December, 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 Lisbon, Faro and Porto. 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.