For cities with a population above 200,000, Gijón in Asturias and A Coruña in Galicia are the coldest during the summer season. Their average high temperatures between May and September range from just 18 to 23°C (64−73°F).
Where in Spain isn’t too hot?
Northern Spain ( Galicia, Asturias, Cantabria and Basque region )is reasonably cool in the summer.