Why does it get so humid in northern Appalachia and the Midwest (Chicago for example)?

Question

I mean, it's not like these places (New York, Illinois, Ohio, Pennsylvania) are close to the equator like Florida or Puerto Rico are. Why does it get so humid in these states? It seems like it should be dry because they are so far north of the equator and the tropical zones.

Please don't say it's all due to global warming either because I lived in PA in the early 80s and it was hot and humid way back then too.

Answer 1

Your supposition overlooks the geograpy of the Eastern part of the US and the quirks of meteorology. In the summer, a "Bremuda High" sets up off the eastern coast. Since the US is on the west side of the high, the wind circulation is from the south and southwest, bringing in winds off the tropic Alantic and Gulf of Mexico. Should this high drift westward, the humid flow shifts westward to Illinois and Ohio (and I suppose Indiana too). A strong high leads to prolonged heat and humidity, as the cold fronts from the northwest flow up and over the high rather than push southeastward. There have been years where the high was not very strong, and in that case, summer weather tend to be cooler and less humid.

Answer 2

Chicago can get very humid. but it isn't going to be humid everyday during the summer. and our temps are a little lower than yours. Plus we have wind. almost everyday. We just had company in from CA. and they commented on how the trees are always moving. In Downtown Chicago by the lake front, it will be a little cooler than the outskirts of Chicago. You got the wind off the lake. You may need a sweater for early morning or late at night right now we are getting hit with some hot weather, with no rain. Nothing you can't handle coming from TN.

Answer 3

Well, it IS due to global warming. But the temperature difference between the 80s and today is at most a few 10ths of a degree, not something you're likely to notice.

No, it's due to a couple of major factors:
*Lower altitude - denser air keeps heat and humidity in better than thin air.
*Distance from the jet stream - most of the time the jetstream passes north of places like missouri and mississippi and all of appalachia. The jet stream pulls cold air with it - but not here.