I am new to this and will start my first Camino around the 5th April from SJPP.
I can appreciate what variants of weather and changes of altitude can make at that time of year, which makes a person worry about being warm enough.
As an old soldier, can I pass on a tip?
Carry a pair of women's pantihose with you. They are cheap, light weight and disposable, Under long pants, pantihose can keep the best of us warm and I can say that after many cold, wet nights on guard, where good army long johns just did not have enough heat.
A pair of rain pants also make a good simple alternative in beating a biting wind.
If you are cold around the upper torso, a newspaper between shirt and jacket,will help you stay toasty warm as well as give you something to read at lunch time! I learned that from standing up in the turret of a tank.
Believe me, these ideas work.
Should you see someone on the Camino in April stuffing a newspaper inside his jacket, stop and say Hi and if you are cold you can have the sports section. I never read that!