When the temperature outside drops enough that you can keep your precious beer cold without the use of a traditional fridge. If it's cold enough outside, its more effective than the old-fashioned fridge.
"Hey I'm going to the kitchen, y'all want another beer?"
"I didn't put the beer in that fridge, it's outside in God's Fridge."
"I brought a case o' beer while we watch the game, where do you want it?"