The weather in Spain might not be what you expected...Image: Manuel M. Vicente
Unless you're in Andalusia, the year starts cold in Spain. Hardest hit are the high altitude central cities like Madrid, Toledo and Salamanca or, more precisely, the countryside around these cities (cities usually protect themselves a little with their own warmth). In Madrid it is not uncommon to get a mini 'heatwave' (of sorts) in January or February when you can at least sit on an outside terraza drinking coffee without the need of a coat!
To the north and south of these regions things are a little warmer. Andalusia will still be reasonably warm and sunny while the north coast will be warmed slightly by the Atlantic. Galicia (in the north-west) is extremely wet - expect up to 20 days a month of rain during the winter in these parts.
As you can see from the picture, Spain does get snow. The likelihood of snow depends largely on where you are in the country. Spain's mountainous regions are the most likely regions for snow (which is lucky for the ski resorts!). Andalusia has little (apart from in the Sierra Nevada mountains) and Madrid and Salamanca are usually too dry (which means beautiful blue skies even when it is freezing! The north coast on the whole is too warm - you get more rain here than snow. However, when snow does hit this region, as it did in January 2006, expect it in huge quantities (several feet).