I've figured out what I need to stay warm when it's below .. say .. 45 on the course. This is what I wear:

Two pairs of socks
Long underwear
Cargo pants
Mock turtleneck compression shirt
Zipper v-neck jersey shirt
Golf vest
Windbreaker
Stocking cap

I wore this getup on the course this weekend when it was around 40* with an 8-10 mph wind, and was quite comfortable. I wear the golf vest under the windbreaker, and usually have the windbreaker off by the second hole. Honestly, I think the most important thing on the list above is the hat. I don't get cold unless I take it off.

What does your cold weather outfit look like?

Similar to you. One pair of good wool socks, long underwear bottoms, slacks, turtleneck, sweater, a rain jacket or windshirt and a sock hat or beanie. If it is really windy or wet, I sometimes swap out the slacks for good quality rain pants.

This outfit is fine down to 32 degrees as long as I walk the course. It often seems "too cold" for the first hole or two but once one gets moving, it can be surprisingly comfortable, especially if there is a bit of sun. As I have mentioned before, I don't like to play when the greens are frozen. With rock hard frozen greens it is no longer golf. I imagine I could play at 25 degrees or less but what's the point?

Nice topic. Dressing warm has become sort of a hobby for me lately. LOL. On an average cold day I put on one pair of warm socks, silk thermals and chinos or (forgive me) regular denim jeans. I only tried the denim recently and I like it because they jive well with the thermals. Alternative to all this layering on the bottom is flannel-lined chino pants, available at jcrew.com (full disclosure, my GF works for them, 90% of all my clothes comes from here). When its really cold though I tend to go with the thermal layering.

On top I like to go regular t-shirt, fleece pullover topped with a windbreaker. Kind of minimal but this seems to work best with the swing. Synthetic fleece is the key, offers a lot of warmth without being heavy or thick. Cashmere's pretty good too if you are a fancy sort. If its especially cold I'll wear an Under armor compression mock thingy topped with a vest and then windbreaker. The Under armor is amazing at keeping the body heat in but it feels a little weird swinging the club.

As you say Steve the hat is crucial. No matter what you are wearing it is hard to feel warm when the old noggin is not well insulated. I just got a Patagonia fleece lined beanie which works wonders. Gloves are also a big deal IMO. On the left I wear a regular golf glove and keep it on the whole time, and in between shots cover the right hand with a Polartec fleece winter glove--I have found that this really helps the overall sense of warmth.

It's pretty harsh out there today but all this talk is making me want to get the layers out and tee it up.

I am a sick puppy that is a native Floridian, and feels absolutely out of balance golfing in long pants. I played on Friday, 43* 15mph wind wearing heat gear underwear with shorts, anklet socks, one golf shirt, one lightweight wind shirt, hat, with the one concession being I wore two gloves, because thinning a ball in those conditions just kills your hands otherwise.

On top of that, I got paired with a guy passing through from Minnesota who was all bundled up and wearing his rain gear.

My cold weather gear consists of sweat pants and a sweatshirt, since the golf courses are closed by the time it's gotten too cold to wear my normal clothing to the cours.e

I wear shorts and a polo shirt no natter how hot/cold it egts

Lately I've been wearing a sleeveless tee shirt then an old turtle neck with sleeves cut off above elbow overtop that. Then short sleeve rain pullover topped off with lined jacket. Footjoy weather gloves. Jeans. Heavy socks. I'm thinking about one of those Russian winter hats w/flaps.

Today I stayed warm in 30's degree temps. Under-armor coldgear mock t-neck topped with a Patagonia "synchilla" fleece vest topped with a windbreaker. Man it was a winning combination, kept me toasty all day. 30s is not so bad after all, I'm ready to do it again.

Atta boy. You eskimo.

Today it was sub-freezing. Not insane cold but pretty serious. I hit a lot of shots without taking off my winter glove. LL bean polartec fleece. It actually gave me a pretty good feeling of the handle and I made some solid strikes this way. Toward the end I hit every shot with it and can't say that it really hindered anything. The world is my oyster now. The exposed right hand is one of the worst things about extreme winter golf and now that I know I can swing while keeping it protected my threshold just got a lot lower.

Temperature?