Fridge Thermodynamics

Alright, engineer cadets, and appliance-repair apprentice wannabees, I have a story problem for you.  

Imagine a hypothetical beer fridge.  Like many beer fridges, it is kept in the garage – though in the yard, at the end of an extension cord, next to the car up on blocks would work as well for this example … but I digress.  

So, in addition to beer, there is ice cream in the freezer.  Everything works fine, even in the heat of summer (the one in the yard is under s shade tree).  

But a strange thing happens when it gets chilly outside.  It’s all good until it gets down to about 40°F.  At that point, the refrigerator continues to work just fine, but the ice cream in the freezer softens up a little.  Then, when it gets to the mid-30s, everything in the freezer slowly melts.  When it gets below freezing, it hardens back up, but then softens up again between 33°F and a bit over 40°F.  When the weather gets warm again, it freezes up again just fine (though thawed and refrozen ice cream is never really the same again.