Wow! This really reinforces the variable nature of weather on the camino, I guess, especially early in the year. We walked in December and January this year, and certainly it was cold, several times with extremely freezing fierce winds, heavy mist, some stretches of walking through snow underfoot etc , but over the whole 5 weeks we only actually had 2 days of rain and 2 days of some snow falling. We walked over O'Cebreiro with clear skies but could see on the televisions in the bars that the road was closing behind us, and later we met up with pilgrims in Santiago who had been just a day behind us and had been snowbound, waiting in in Ave Fenix albergue (Villafranca del Bierzo) for 3 days.
(take good gloves, we had waterproof caving gloves and a polar fleece headband or beanie and sleeveless shell, mmm, potential lifesavers)