Bilbao, where it lies in the map

Bilbao, the largest city in the Basque Country, is located on the northern Spanish coast, where the climate is different from the rest of Spain, being temperate oceanic, with mild and rainy winters, and quite cool or pleasantly warm summers.
Here are the average temperatures.
Bilbao - Average temperatures
Min (°C)556710131515131186
Max (°C)131516172023252624211614
Min (°F)414143455055595955524643
Max (°F)555961636873777975706157

Precipitation is quite abundant, given that it amounts to 1,200 millimetres (47 inches) per year, and it's frequent from October to May, while from June to September it becomes a bit less frequent, so much so that in the latter period it rains on average from seven to nine days per month.
Here is the average precipitation.
Bilbao - Average precipitation

In addition, the wind blows frequently from the ocean, and can be strong, especially in the cold half of the year. On the other hand, the hot and dry southerly wind, which descends from the Cantabrian Mountains, can cause sudden increases in temperature, due to the foehn effect.
At night, fog can form, especially in autumn, and a little less frequently in spring.

Winter, from December to February, is mild and rainy. The average temperature in January is 9 °C (48 °F). Atlantic disturbances pass regularly, bringing rain and cloudy skies.
Cold spells are quite rare, and don't produce remarkable effects; however, there may be some cold days, with highs around 5 °C (41 °F); snow is a rare phenomenon, though not impossible. At night, slight frosts can occur, typically one or two degrees Celsius below freezing (0 °C or 32 °F), although in January 1985 the temperature dropped to -7 °C (19 °F), and in February 2012 to -4 °C (25 °F).

Spring, from March to May, is cool, cloudy and rainy. Wind and humidity can increase the feeling of cold. When the wind blows from the south, there may be sudden temperature increases, with the first warm periods, maybe only for a day or two.

In Summer, from June to August, generally the days are pleasantly warm, while nights are cool. Some Atlantic disturbances, which can bring rainy and cool weather, with highs around 20 °C (68 °F), can pass even in summer, although more rarely than in the other seasons, so that there may be entire weeks without rain, even though it depends on the year. Hot days are rare: the temperature exceeds 30 °C (86 °F) for a few days per month, and even in these cases the nights remain cool. Every so often, torrid days are possible, with highs near 40 °C (104 °F), due to the aforementioned down-slope wind from the south, but even in these cases, at night the temperature usually drops below 20 °C (68 °F), and besides, these are usually isolated events, as happened on July 31, 2013, when the temperature reached 42 °C (108 °F) for one day. Only in August 2003, but it does not count because it was an exceptional summer in all of Western Europe, there have been several hot days in a row, and the temperature reached as high as 46 °C (115 °F).

Autumn, from September to November, is cool and rainy, especially in October and November, while in September the temperature is still pleasant, and the rains are not so frequent, so that there is no big difference with the summer, especially in the first half of the month. In autumn, on clear nights, fog can form.


The amount of sunshine in Bilbao is not high, given that cloudy skies are predominant, especially in the long period in which Atlantic depressions are frequent, ie from October to May.
Bilbao - Sunshine

For swimming, the sea is very cool, if not a bit cold, even in summer, since its temperature reaches at most 20/21 °C (68/70 °F), from July to September.
Bilbao - Sea temperature
Temp (°C)131212131518202120181513
Temp (°F)555454555964687068645955

When to go

The best time to visit Bilbao goes from June to mid-September, being the warmest and driest of the year. It's better to bring a sweatshirt and a light jacket for evenings and rainy days; even an umbrella can be useful.