Albedo is a word describing the portion of the sun’s radiation reflected from a surface. Most sunlight passes directly through air with relatively little absorption. The reason it is usually warmer in the afternoon than at night is because of solar radiation heating the ground and the ground then heating the air via convection. Snow-covered ground has an albedo between 0.40 and 0.90, meaning snow cover reflects 40-90% of the radiation (light and heat) coming in from the sun. This is why a snow-covered field is so bright on a sunny day and also why snow cover makes our weather colder.

Dark, wet soil, on the other hand, has an albedo near 0.0, meaning it absorbs almost all the solar radiation it receives. This time of year, it is likely that all the record highs were recorded on days with little to no snow cover, and all the record lows were recorded with deep snow on the ground.

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