Crandall:
I have started all my Camino's between March 23rd and April 11th. Spring in my opinion is a great time to walk but honestly my decision to walk then is based more on the convenience of that time of year.
Weather, imo, should not be the determining factor in deciding when to walk. It is just to unpredictable. My first two Camino's I walked the Napoleon route on March 23rd, no snow. Now you can not even consider this route prior to April 1st. That said, the ValCarlos route is better, imo. A much more gradual start, the break ValCarlos is a town with all the amenities and you still walk over the mountain.
The weather will vary from cold mornings in the mountains to very warm days on the Meseta. So come prepared. Rain gear is a must. That said, I have walked weeks w/o wearing it. It also serves as a nice wind break in the mornings.
Therefore, I do not think you decision should be based on what the weather might be but on what is the most convenient time for you. If you are prepared the weather should not be a factor and it is not predictable.
Ultreya,
Joe
PS: Easter week can be quite hectic but also very interesting. It Falls on April 12th this year.