Hi Peter
I started on 22 September last year. It was very hot but manageable for the first week(s).
The sun is highest and the day hottest after 2 pm and later - due to Spains time zone - and sunrise is late.
Suggestions -
Start early - 6.30 am or earlier - it will be dark so a good headlamp is a blessing. Others will be on the road at that time. The scenery is pretty much the same all day but the stars and sunrises are spectacular. Some people in some sections started at 5.00 am. (I took a bus for that one 30 Km section).
Finish before 1.00 pm before the temp gets too high. I walked In the afternoon a couple of times. It was really hard but also showed me I was stronger than I thought. But would definitely avoid this if possible next time.
Sun protection- I had a reflective umbrella which was a lifesaver. I met two Swedish sisters who had these literally cool caps that you put in the fridge overnight and they stay cool on your head all day.
Late September is great - hot, passionate, challenging … I actually missed it when I got to the hills.
And finally, you arrive in Galicia before the weather gets too cold.
Buen Camino
Edit- I didn’t experiment any shortage of accommodation (except for weekends in tourist towns like Mérida) and most albergues were open. With Gerard Kelly’s guide and gronze it wasn’t too hard to plan my days.
I loved this Camino even though I did hate it a bit at the start.
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