I think this is true. I know its a topic of discussion on here and some say its just that you hear about it more in winter. I swear I heard somewhere that since its generally cooler in winter, viruses can live longer, whereas in the summer when its hot, the heat kills them. Like when you want to sterilize something, you boil it. When you want to make sure bacteria is killed in meat, you cook it. Maybe I'm just making that up in.my head somewhere, but I'm pretty sure I heard it somewhere. That's also why the flu goes around more in winter.