The most important factor in the climate of Bilbao
and the surrounding lush green Basque countryside is the steady
drizzle called the sirimin. It imbues the atmosphere with a
steady grey, one that lets up little and rarely. Summer and autumn are
better than winter and spring in terms of the rain.
Bilbao has the classic four seasons – spring (March
to June), summer (June to September), autumn (September to December)
and winter (December to March). The average annual temperature is 14º
C and winter lows seldom go below 0º C. Summer days are usually a
pleasant 20º C.
