I buy a lot of golf attire. Most that you find anymore seems to be best suited to really warm weather. Shirts, shorts, pants all are made of very lightweight, moisture wicking material.
Because I live in a cold-weather climate, HALF of what I buy are items like Under Armor heat gear shirts to wear under golf shirts. Also buy a lot of windproof, zip up to the chin overshirts. Also have to have a rain suit because you never know when the weather will change. Lastly, I have a nice Nike jacket that was made with golf in mind. Wind, water resistant, zips up to the chin, light weight but keeps me warm in temps around 50 degrees.
Brands of clothing and accessories I buy: Nike, Adidas, (mostly) and the occasional Oakley, Puma or Under Armor.
I also like playing in warm weather wearing shorts and golf shirt only. I do own a couple pairs of golf slacks/trouser, but prefer wearing shorts over pants.