True we really cannot guess the weather! Thank you for message.
@Trekker One did you experience much rain?
2014 & 2015 (spring Camino's), zero rain, never got out poncho once.
2016 (spring Camino) heavy snow first couple of days, used poncho and then one other day about a week later.
2017 (spring Camino in Portugal), zero rain and unseasonably hot.
2018 (Primitivo in late September) zero rain and very warm every day.
2019 (spring Camino) started unseasonably warm, but changed to snow and rain for a week, then back to nice weather.
2021 (fall Camino) dry and quite hot in late Sept., early October. Zero rain.
Total use of a poncho on seven walks, maybe on 14 days total. Shorts and T shirt by mid morning the norm on almost all days spring and fall.
I live in northern Alberta where -35 C is not uncommon in the winter, so my perception of what is cold may differ from others.
If it is 3 to 5 C, I am always in shorts, but layer up above the waist when starting out in the morning.
I do cold really well, but hate long days when it is 30C or above. Can't imagine doing a walk between mid May to mid-Sept.