Kansas weather is a lot like Iowa weather only Kansas gets it a day earlier.
Heavy winter coats, hats & boots 'might' be necessary if you are going to attempt to drive thru a blizzard.
Inquire at the car rental desk as to what necessary provisions you should purchase at a C/store for your trip to the Ft. The skies may be clear and balmy. You just never know.
Maybe we should stock up on outerwear from Cabela's before we leave! :-)