Temperatures
Temperatures throughout most of this region are very moderate. They see four full seasons, but the winters are neither as frigid as in the northern states nor the summers too long and hot, as in the deep south. For instance, the average July temperature in the city of Baltimore, Maryland, is 77 degrees F. Winters hover at or around freezing: the average temperature for January is 31.8 F. If you move west towards Ohio, those temperatures cool a little, while in South Carolina they grow warmer.
Precipitation
The Mid-Atlantic region is a wet one. Rainfall occurs steadily throughout the year, with snowfall in winter months. Pittsburgh, Pennsylvania sees nearly 37 inches of rain a year and 44 inches of snowfall. Other areas receive more rain and less snow; the District of Columbia, for instance, averages closer to 40 inches of rain and 20 inches of snow. Moving south to Charlotte, North Carolina the snowfall decreases dramatically, to only 5 inches, but rainfall remains above 40 inches a year.
Humidity
When you factor in both precipitation and proximity to the Atlantic ocean, it is not surprising that these states experience consistent high humidity. Average humidity throughout the year for Wilmington, Delaware is 70.5 percent, with the most humid months being August through October. The two most humid months are December and February, but at 57 percent humidity, even their driest month, January, cannot be called terribly dry.
Climate Change
At the time of publication, there is concern in the environmental community because the coastal Mid-Atlantic states are experiencing a higher than average sea level rise due to climate change. Oceans around the world are rising 1.7 millimeters a year, while states like Maryland and Virginia report rates of 3.53 in Annapolis, and 3.76 in Portsmouth. Wetlands, estuaries and barrier islands may be seriously affected over time, leading to an increase in wide-spread flooding and loss of plant and animal habitats.