"cold day"

One phrase that Evan's been saying a lot lately is "cold day". What he really means is "cold", but instead he always appends the "day". I think it's because likes to go out and play in the backyard first thing in the morning, and during winter/spring months it's too cold to go out, so we'd always say to him "cold day" and make the shiver sign. Now when he washes his hands in cold water, he says "cold day"; roll down the window of a car, he'll say "cold day". Eat a few bites of ice-cream -- "cold day!"