The in-between months: a long sleeve, tights or shorts, and a shell you can tie round your waist (sample guide).
Kit notes
Notes from the shop counter: what to wear at which temperature, how running shoes should fit, how to wash merino and waterproofs, and what has just come in.
A base layer that wicks, a fleece that traps air, and a shell that keeps the wind out (sample guide).
Wash cold, skip the softener, hang it up: synthetic kit is dry by morning (sample guide).