"Hurm. Pretty thick layer of frost on the cars this morning."
A minute later, "It's really not all that cold out here. Wonder where all this frost came from?"
And a minute after that, "Damn, look at that, there's even frost on... the rooftops--
"Fuck me, it snowed last night."
So I walked up to the trunk of a car and ran my hand across it. It had started to melt in the sun and re-freeze in the below-freezing temps, but enough of it came away in my hand to confirm my theory.
It was a very pleasant moment.