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Snow on trees
We have already had our first snow of the year. The day it snowed, the low was only 36°F. If the temperature is above freezing, why did the precipitation not fall as rain?

Answer:

The temperature at ground level has much less to do with the different kinds of precipitation than does the temperature in the upper atmosphere. If the air above your house is very cold, you can have snow when the air outside your house is well above freezing. It works the other way too. Warm air at higher altitudes can give you rain, even when ground level air temperatures are well below freezing. This is what gives some of the worst ice storms, with precipitation falling as rain, and then freezing after it lands.
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