I live in the Atlanta area so compared to a lot of places, it doesn't get too cold here (though I find it very cold).

Last year, I ran my first 10K in February and it was between 20 - 25 degrees and raining. I ran in clothes (a top) called Cold Gear (some brands may call it Sub Zero) and was very comfortable throughout the race. The clothes are lightweight and still have that wicking technology (what I call "breathable").

I posted a couple of links to brands that my husband and I have (SUgoi) or have considered (Under Armour):

http://www.sugoi.com/consumer/section.aspx?id=2045 - tights, pants, capris
http://www.sugoi.com/consumer/section.aspx?id=2043 - long sleeve tops (I wore the speedster for my Feb 10K)

http://www.underarmour.com/Product.c...=1&coll_id=103

Hopefully you find this information useful.