Lots of good info here already. I've lived (and ridden) in Missouri my whole life. Can agree with much above. Typical (if there is such a thing) weather can be somewhat predictable, such as: a cold front comes through - line of (possibly severe) storms, with maybe several hours of rain afterward. The day after it is clear, relatively cool (80's), low humidity (dewpoints in the 50's). NW wind, how strong depends on how strong the cold front was. The second day after the front may have very little or no wind, then over the next few days gradual warming (upper 80's to maybe 90's)and the wind swings around to the SW, dewpoints rise through the 60's, may get into the 70's. After four or five days the cycle starts over. Frequently over the last 24 hours before the next cold front winds can become pretty strong from the SE or E and usually the day of the front it's a strong S or SW right up to the gust front and torrential downpour. There is a lot a variation in the above - not all fronts bring severe storms; sometimes you get under domes of high pressure and it's just hot and dry (usually later in the summer), etc., but the above will give you a bit of an idea of mid-May through June weather in the Missouri - Illinois - Iowa region.