A light snowmobile suit and a Parka! (no kidding; that's Minnesota!!)
Sure it's cold in the winter, but it's nothing like Minnesota (I lived in southern MN 2 years and it was SO much colder than Ames). So more Northern climates can be much worse than Iowa. You do have to put up with the winters.
But the Spring and Fall are very nice, the Summers are too (compared to Southern climates). You can actually go outside and do stuff in the summer time in Ames. Compare this to the South, and it's really not that bad. It might actually have some appeal.
I live in the south (nashville). This won't be a popular opinion, but living in the south (in terms of climate) is way better than living in iowa. You can still do things in the summer. Much like northern folks acclimating to the cold, southern folks acclimate to the heat. Saying how much worse MN is than Iowa doesn't make Iowa winters any more desirable IMO. They both suck. I hate the cold. It was a major factor in me leaving the midwest for greener pastures in terms of weather. To each their own. Give me the heat all day over the Iowa cold.