My son has a barky cough/raspy breathing?

My 2 1/2 yr old woke up just a little bit ago with a barking type cough and kind of raspy breathing. He was fine when he went to bed and he doesn't feel like he has fever or anything. He does sound a little congested and his nose is runny, but other than that and the growling sound when he breathes real hard he seems fine. Should I worry about it tonight (we live 35 min from the ER) or is it something I may be able to wait until tommorrow on? And what could it possibly be?