Wife and I go there all the time ,
well .................everyone in NW Iowa go there all the time....................lol
Nah , you probably won't need your Thermals..................lol
I would bring a warm coat though , April in NW Iowa has no idea what it wants to do , 75 and sunny on one day , the very next day , 35 and raining
Without looking it up , I would guess the average highs are in the 50's and lows in the 30's , but I will pretty much guarantee one thing , the wind is going to blow 40 MPH every single day , take today for example
Rains a lot in April also , I always call it the mud month , all the snow has pretty much melted , turning everything to mud , plus the Spring rains are starting , April can be a pretty wet month , but you'll probably beat all the tornados , they won't show until about May and June......................LOL
Welcome to Iowa , you're grandson will get to enjoy all 4 seasons.................lol
But I'll bet you'll like it there , nice quiet , small towns , real friendly people , , I think I mentioned before a lot of Dutch heritage in that part of the state , I don't know a whole lot about Dordt College , other then it has a very excellent reputation
Iowa in April