It really just depends on the person. Some people wear waders in July fishing in a foot of water, other will wet wade in March.
Personally, I usually don my waders around the end of October/first of November and I am wet wading by the end of March/first of April.
Wet wading gear for me is PGF quick dry long pants, neoprene booties, and wading boots. Long pants to fight of the nettle.
Wild troutin, blue linin, fly flingin, camo wearin, redneckin elitist.