Don’t start a round cold, because you’ll never get warm (in a golf cart especially). I won’t dress for cold on the golf course. I dress for it in the locker room or at home and then warm up extra well. Preparation again. If you have to shed clothes as you go, shed them. But start off warm.
I always pack silk long johns to put on under my slacks. I add my rainsuit bottoms, and my legs are always toasty. On my upper body I will wear a turtleneck and a sweater, plus a windshirt and/or rain jacket, depending on the temperature and windchill factor. I like these layers of clothing to be as flexible and quiet as possible. They aren’t so bulky that they hamper my swing.
A ski cap keeps my head warm. A lot of body heat can escape from your head. It’s critical playing golf to keep your hands warm. If your hands get cold you can’t play. I like to keep my hands in my rainpants pockets until I’m preparing for a shot. I’m lucky: My former caddie, Bruce Edwards, would hold the umbrella over me when I’m walking in a cold rain so I can keep my hands dry and warm in my pockets. If your rainpants don’t have pockets, wear a pair of down ski mittens between shots—a size larger to fit over your golf glove. Carry a hand warmer. Do whatever you have to do to keep your hands warm so you can feel the club.
I’ll warm up before my round by briskly walking a quarter of a mile or more before I ever stretch or swing a club. It gets my blood flowing. Then I’ll do the series of stretches I’ve talked about doing before any round of golf, for at least 10 minutes: the side-bend stretch with the club held at both ends (left); the behind-the-back stretch, where I raise the club as high as I comfortably can; the torso twist, where I rotate both ways in a simulated address position; and the shoulder stretch, where I pull one arm across my chest. I finish with some full practice swings and, finally, hit some practice balls.
If you have the option of walking, I strongly recommend it to stay warmer. Riding in a cart creates its own headwind. There’s a good selection of lightweight Sunday bags on the market, and you don’t need to carry a full set of clubs. It can develop your shotmaking skills to play with fewer clubs.
The ball won’t travel as far in cold weather. You lose about two yards for every 10-degree decrease in temperature—and more if the ball itself is cold. (When the temperature drops, Bruce would put a hand warmer in his pocket and keep my golf balls in that pocket before I play.) It can be enough to influence club selection, especially if your swing is already affected by the cold. A cold ball certainly feels harder around the green, but performs the same.
When cold combines with wind and/or rain, you have to adjust accordingly. Or, if the weather is too bad, wait for a better day and work on your game indoors.