Build a breathable base
Start with a long-sleeved shirt, light knit or tee plus cardigan, depending on your activity. A tightly packed train and a slow outdoor walk ask different things of the same outfit. Choose a base you would still be comfortable wearing once the outer layer comes off.
Add one adjustable middle layer
A cardigan, overshirt or thin fleece provides warmth without forcing you into a heavy coat. If you run warm, use an open layer that can be vented. If you feel cold easily, a fine knit under a light jacket can be easier to regulate than one thick jumper.
Dress for the day, not just the number
Start with clothes you already own. The forecast tells you which layer to carry, not which outfit to buy.
A comfortable base, knit and light outer layer. Take one off when you warm up.
Keep the base and carry the outer layer. Shade and wind can still change the feel.
Choose shoes for wet ground and swap the outer layer for a rain-ready option.
Let wind and rain decide the outer layer
A dry, calm 15°C afternoon may need only a light jacket. Wind or rain at 10°C can call for a more protective shell and dry socks. Check the hourly forecast and your travel time; a label like 'autumn outfit' cannot replace those details.
Finish from the ground up
Closed shoes, comfortable socks and hems that stay off wet pavement make the outfit practical. A scarf can be an easy removable adjustment. Before leaving, try the complete look indoors for a few minutes, then carry the layer most likely to be needed later.