Defining the Not-Midwest: Climate

The interior lowlands of the United States are characterized by a largely humid continental climate.  This means that the vast landmass of North America produces winters in the region that are cold, sometimes downright frigid, and a bit on the drier side.  At the same time, the Gulf of Mexico, perhaps the most powerful humidity factory in the world, aside from the South China Sea, sends north a lot of hot, extremely humid air.  This produces not only the sweltering summers of the region, but also a conflicting air mass, that, when colliding with the continental air masses, spawns some of the most violent non-oceanic storms in the world.  While these two contenders are normally the main event in weather showdowns in everything east of the Rockies, there are alternative influences that sit on the sidelines ready for the tag to get into the action.  The greatest of these, at least in the northeastern United States and parts of Ontario and Quebec, would be the Great Lakes.

The lakes are huge, hundreds of feet deep, and as such rarely freeze over in the winter.  Lake Superior and Lake Michigan have never reported total ice coverage, though Michigan came close in the late seventies.  Open water has a tendency to moderate air masses that pass over them, even if the water is on the colder side.  For Michigan, northern Ohio, northwestern Pennsylvania, southern Ontario, and western New York (see a theme here yet?), this gives such places air conditioning in the summer, and longer growing seasons as well as moderation of arctic air masses in the winter.  Also of note in the winter, the areas within sixty miles or so of open water can see massive amounts of snow thrown upon them, called lake effect snow.  Rainfall totals are higher here than in other parts of the interior, often by as much as 10 inches per annum.  In terms of normal interior weather, these areas largely see quite different effects than much of the rest of the land does.  Tornadoes are possible in Michigan, Ontario, and northern Ohio, but they are often much smaller in raw power than the terrors that can strike places like Joplin and St. Louis.  Storms, waves of extreme temperature, even relative sunshine, they all get muted by the Lakes.  Sometimes it even seems as if air masses tend to stick within state lines.  Just look at Wisconsin and Michigan here!

Or for those curious about how this works in the winter, take a look at this map:

Obviously Ohio is behind an arcing front, and is thus colder than Indiana, but Michigan?  Not so much.  Yes, Lake Michigan is quite the attractive piece of water.  The Lakes influence the temperatures of these lands enough to give places like the Grand Traverse area of Michigan and the Niagara frontier of New York and Ontario a growing season comparable to what can be found in Kentucky or New Jersey.  If this sounds like a stretch, one need merely venture out among the extensive orchards and vines of these otherwise northerly latitudes.  Niagara-on-the-Lake, in fact, actually has a climate that supports several species of cold-hardy palms.  The peak fall foliage times is often late October and early November.  Best of all, spring blossoms last much longer.

So, what does this mean for the Midwest and Not-Midwest besides what will fall from the sky and how warm things will be?  Come by next post to see what defines the differences between these regions in terms of geography.