The temperate deciduous forest occupies much of the middle of the Whittaker diagram, and to those of us who live here, it sure feels that way. Rapid changes from cold and dry to wet and warm or to any of the other corners of the climate envelope are often swift and dramatic. A favorite saying among the natives is "if you don't like the weather, wait a minute". Of course, we are talking about climate here, not weather, but the principle remains. Over the course of the year the climate will range from cold with precipitation in the form of snow, to hot, with precipitation in the form of rain. Precipitation may vary with the seasons as well, with some seasons being wetter than others.
As the diagram indicates, the average annual temperature ranges up to about 20� C down to freezing. Precipitation ranges from around 50 cm yr-1 in the colder regions to over 200 cm/yr. In Ohio, at least, we tend to have most of the precipitation fall in the spring and early summer, with late summer and early fall being dry. We get rain or snow in the late fall and winter, depending on where in the state one is. In northern Ohio, Lake Erie moderates temperature in the fall, resulting in a band around the lake where the first fall frost is noticeably later than it is a few miles inland. Historically, this area (an similar regions in New York) have been good for growing grapes. The (relatively) warm waters of Lake Erie are also responsible for lake-effect snows in the winter (until the lake freezes). Air coming across the unfrozen water picks up moisture which falls as snow; this is particularly noticeable in the "snow belt" which extends from Cleveland to Buffalo - although sometimes that snow may fall as far inland as Pittsburgh. On the other hand, spring comes late in northern Ohio as the now cold water of the lake puts a chill on things. The cool lake waters do make for a cooler and less humid summer as well.
Southern Ohio has a different feel to it. Snow is not as common in the winter, although a snowstorm or two is not uncommon. Long stretches of below zero temperatures are not very common, and the norm is for the temperature to get above zero at least part of the day. The summers are hotter, and, at least along the Ohio River, much more humid. I grew up in Ohio and have lived in 4 different parts of the state. The impact of global climate change has been noticeable; there is less snow and the winters are warmer than when I was a kid (and had to walk to school through 6 feet (2 meters) of snow, uphill both ways).
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