Where I live, it can get pretty cool. I'm about to invest in a wort chiller but am thinking that it will be no warmer than 15 degrees from December to March. Maybe I can just cool my beer on the porch?
You could but it would take quite some time. You really want to cool down to the 60's as quickly as you possibly can in order to picth the yeast & stave off any baddies taking hold. If you live in a snowy climate, you can always get a Rubbermaid tub, fill with snow & put your brew pot in there replacing the snow/ice as it melts. That's a low cost way that would work quicker than just air temp cooling....
Just look up the no-chill threads here. I just did a no chill last weekend. I don't plan on doing it for hop-forward beers, but for malty ones, seems to work great. Some people leave it in their kettle, others drain it into a corny keg or plastic carboy and seal it to keep bugs out.
After a good snow... just drop the pot in the snow! keep its packed around it and it'll cool down really fast!
I can cool mine already in an ice bath within 20 mins, but I dont tend to boil more than 3 gallons.