Fahrenheit

0 = Well below freezing, about as cold as it gets anywhere that isn't frozen year-round. Dress like you're climbing Everest.

25 = Just below freezing, very cold but not record breaking anywhere people own snow shovels. Bulky jacket and gloves.

50 = Cold to cool, depending on your baseline. Put on a thick sweater or a jacket.

75 = Perfect, slightly above room temperature. T-shirt and shorts.

100 = About as hot as it gets anywhere that isn't a desert. Tank top and sunscreen, and stay in the shade.