Hi Singingheart,
I have been lucky enough to walk twice in September and October I would say it depends how thick your fleece is? I will repeat my first stage again this year and will have again an
Altus poncho with good fleece and extra long sleeve item to add if necessary. (Merino sweater for me)
First year I did have a couple of frosty mornings and would agree with the need for gloves and something to warm your ears, having said all of that most of the time all my stuff was carried and I had blazing sunshine for most of my days! Bring sun protection!I was grateful for my extra clothing at night in a few cooler Albergues but when I was walking I soon wanted to shed layers. I love the weather in the later months and don't ever envisage walking any other time than the Fall, my son had 35 out of 42 days of rain during his Spring Camino!!!
I wish you a Buen Camino I'm hoping to leave St Jean around the 18th of September this year, maybe see you out there?
Sarah