You can enjoy Andalusia all year round, however, it is advisable to avoid the months of July and August, which are very hot, sometimes making for unpleasant holidays.
The centre of the country, particularly the Madrid region, is isolated in the mountains and situated in a basin: the summers are hot and dry there, and the winters are cold, but it doesn't rain much throughout the year, making a visit to this region of Spain always very nice.
The best thing to do is to favour the off-season months, in the spring and fall, to avoid the crowds and the intense heat, although temperatures rarely get above 35 degrees in July and August.
The regions of Catalonia and Aragon have a pleasant Mediterranean climate. The weather is nice all year round, and it's nice even in the summer, thanks to the sea air. However, for those who want to bathe or swim, it's better to go suring the summer months, from June through September! The leading city in the region is Barcelona, and the major draw for the region is rest and relaxation, perfect for those who like to relax on holiday.
Spain is teeming with archaeological sites and monuments, and visiting them is a must for any trip to Spain. The Andalusia region is especially abundant, and it's home to a major part of Spain's historical heritage. The capital, Madrid, should also be visited, to explore the country's artistic and historic potential. These two regions are very hot in the summer and mild in the winter.
The weather is nice year-round in Spain, and depending on which region of France you live in, it will be pleasant year-round to go for a long weekend, to enjoy the heat or mild temperatures. For long weekends, it's better take advantage of the off-season to avoid the stream of tourists, and to take advantage of mild temperatures while it's cool back home. The winter is also nice, especially in the South, but there aren't many activities to get involved with, and there's nothing big to do!
Spain's Atlantic Coast is very similar to the climate found along the coast in England. Winters are cold and grey, while the summers are warm and pleasant. This is the region where it rains the most, so it's also a very lush and green area. Since there are a lot of mountains and valleys, the climate is conducive to trekking and other activities.