Any weather is good weather for catching them. Some of it isn't so nice if you aren't catching any.
My experience is that the best fishing is when it is a little to cold to be comfortable on the water when you are dressed like you were on land or a little too windy to not have to fight the boat.
Best day I ever had fishing for crappie was wearing a down coat, face mask, ski pants and pac boots and I ended up with burns on my cheeks from the tears the wind caused.