Atlanta has an average elevation of roughly 1,000 feet and is approximately 250 miles from both the Atlantic Ocean and the Gulf of Mexico.  The Southern end of the Appalachian Mountains extends into North Georgia and this, coupled with the nearby bodies of water, has a great impact on the climate of this area.  The mountains to the North tend to hinder the movement of Polar air masses so Atlanta has a mild winter climate with some chance of snow in December and January.  The average annual snowfall is 1.5 inches, but snowfall over 4 inches occurs about once every 5 years.  Most snows last a very short time since they are followed by warmer weather.  The first frost is usually in early November and the last frost is usually in late March.  In the summer, high temperatures and humidity are common.  Dry periods tend to occur in the late summer and the maximum numbers of thunderstorms occur in July.  Locally severe thunderstorms tend to occur in March, April, and May and sometimes spawn damaging tornadoes.  The average annual precipitation total is about 48 inches.  Areas of Georgia, though, such as Black Rock Mountain State Park, often receive over 80 inches of precipitation in a year.