Typically, the city experiences a transition from summer to autumn during this month. Average high temperatures hover around 23C (73F), while lows dip to about 14C (57F). Rainfall becomes more frequent compared to the drier summer months, with an average of around 100mm spread across several days. Sunshine hours decrease to approximately 6 hours per day. The Cantabrian Sea’s influence moderates temperatures, preventing extreme heat or cold.
Understanding the climatic conditions prevalent in the Basque Country during this period is crucial for planning various activities. The pleasant temperatures make September an ideal time for exploring the city’s cultural attractions, such as the Guggenheim Museum Bilbao, or enjoying outdoor pursuits like hiking in the surrounding hills. The shift towards autumnal weather also marks the beginning of the grape harvest season in nearby Rioja wine country, presenting opportunities for vineyard visits and wine tasting. Historically, this period has been a time of transition for the region, moving from the bustling summer tourist season towards the quieter autumn months.
