If you're looking for summer vibes, the best time to travel to Bilbao is in July, August and June, when the average temperature reaches 25.32 °C, while August, June and September are the 3 sunniest months of the year, with an average of 95.55 hours.
However, if you prefer colder temperatures, make sure you visit Bilbao during January, February or December to experience an average of 2.68 °C.
For those who don't care too much about temperatures, but want to avoid getting wet in the rain, it's important to avoid travelling during January, March and May, when the average precipitation in Bilbao is 6.75 mm, while the months of January, February and March are drier, with an average of 0 mm.