" year, most of them between September and April.7 This works out to about one a month. These colds last on average fourteen days.8 A month is thirty days. So in the winter, on average, your kid will have a cold 50 percent of the time. On top of this, most kids end their cold with a cough that can last additional weeks. It adds up. "

― Emily Oster , Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool