Porto and its metropolitan area feature a Mediterranean climate ( Köppen: ''Csb'') with mild wet winters and warm dry summers. According to the Troll-Paffen climate classification, Porto has a warm-temperate subtropical climate (Warmgemäßigt-subtropisches Zonenklima), and a subtropical climate according to Siegmund/Frankenberg. Porto is the wettest major city with a Mediterranean climate.

Classifications

Temperature

Normals

Porto has generally moderate temperatures. The average annual high is around and average low around . The climate is also only mildly seasonal, from a maxima of in January to in August, while minima is around in January and in July and August. In its

metropolitan area A metropolitan area or metro is a region that consists of a densely populated urban agglomeration and its surrounding territories sharing industries, commercial areas, transport network, infrastructures and housing. A metro area usually com ...

, January lows can vary between at the coast and on the mountainous interior, and August highs vary between at the coast and in the interior near the Douro valley.

Extremes

Due to its coastal position, temperatures below freezing () are rare, and

frost Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a gas) ...

s are never severe. Porto is placed in the USDA

hardiness zone A hardiness zone is a geographic area defined as having a certain average annual minimum temperature, a factor relevant to the survival of many plants. In some systems other statistics are included in the calculations. The original and most wide ...

10a. The lowest temperature ever recorded in the city was on 11 January 1941.

Precipitation

Porto has abundant levels of precipitation. Despite averaging above of precipitation a year, July and August are relatively dry with around falling each month. The wettest period is between October and February, mostly between October and December, the wettest month.

Humidity

The average relative humidity is around 77%. 81% from November to January and 73% in the summer. Summer can be slightly muggy in the hottest days but is generally comfortable, as temperatures rarely surpass .

Other phenomena

Sunshine, UV and daylight

Despite its precipitation, the total hours of sunshine are relatively normal for a region of its latitude. Winters, especially December, are somewhat dull, and summers are sunny.

Wind

As a coastal Atlantic city, winds are most predominant in winter. In the summer, nortada winds prevail and can refresh the city in the hottest days. The city centre is sheltered and seldom gets any strong winds.

Sea Temperature

1961-1990 data

References

External links

* Climate by city Climate of Portugal {{DEFAULTSORT:Porto