Originally posted by rm-rf
weatherspark.com has weather averages for many U.S. cities. But temperatures can change a lot from day to day.
For instance: Columbia SC (map)
Weatherspark averages. At top right, click F or C to change the temperature units.
Or look at last year's history charts (but last winter was unusually warm in many places)
Or even browse previous months or years in detail (but navigating these charts takes a little practice. You can zoom in or out to see one day, or even years at a time.)