Sarria to Santiago in December

Louise - good luck with your planning. There are a number of websites which give hisptorical information such as: http://www.weatheronline.co.uk/Europe.htm

However the weather has been so unpredictable recently I think the only reliable resource would be weather predictions nearer the time. I think you need to plan for good rain gear and layers of clothing against the cold.

There are a number of packing lists on this site and others. Look at the CSJ webite http://www.csj.org.uk/ which has a huge resource of information and they also have a booklet about Pilgrimages in Winter.

Can you let us know where you are so that members might recommend suppliers to you?