The centre of the country
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.
When to visit the sites and monuments in Spain
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.
When to go to Spain for a long weekend
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!