I've found in the last month or so my pace has picked up considerably though unintentionally. It's been in the 30'-50's (F) the last few weeks and I'm not training for anything just enjoying some runs. My pace is about 30-45s/mile faster than it was this summer. I know some of it probably comes from trying to shakr the cold in the first mile or so, but even later it just feels good to run a little harder than I normally do. I know winter will hit soon (northern Great Lakes area) so I'm trying to squeeze in every good run I can.