If the weather is sufficiently cold to justify wearing it, usually from late Autumn onwards, then i wear my Buffalo Super 6 shirt, it cuts down significantly the amount of clothing required, and really works well.
The rest of the year, i travel light weight, Pertex windshirt, and jacket, and a set of high quality light weight waterproofs, gloves and favourite hat.
From May onwards, the temperature is usually above 10C, and one can get away with travelling with only the bare essentials, water, small amount of food, and light weight clothing.
This combination has worked for me, for well over thirty years, but others i am sure would feel under dressed, possibly venerable if the weather turned nasty.
Check the forecast for the day, pay close attention to any changes in the weather, and if the weather forecast proves wildly inaccurate, postpone the walk for a later day.
Temperature management, is far easier when one has less clothing to worry about.
Wear to much clothing and you over heat, wear too little, and you never generate sufficient thermal temperature control.
Finding that ideal solution on choice of clothing is not easy, but i prefer to wear the minimal amount of clothing, its weighs less, and unless its raining stair rods, is sufficient for the warmer months of May onwards.