2) Clothes – What your wear during your race depends on the weather. Look at the weather two weeks, one week, then every day, in the last week before your race. Does the forecast call for 3°C and rain? Probably not a good idea to think of running in short shorts and a tank top. Think about what clothes you ran in when you were training. If you were training in the winter, for a spring race, you will probably wear something lighter than what you trained in. If you are racing in the fall, you might be wearing more clothes than your training in the summer. I like to think about running at mile 3, how warm would I feel? Being a little cool at the beginning of the run is okay as you will warm up.
My basic set up for running, shoes, ankle socks, shorts, tight/fitted short sleeve running shirt, arm warmers, gloves, wind-proof running vest, toque/beanie (for the first few kms). If it is cooler I might add a long sleeve shirt or a light windbreaker style jacket. If it is warmer I might lose the running vest and arm warmers.
Used from: http://blog.stridekick.com/