Spring, summer and fall are very temperate in my opinion, that's why you won't find many complaints about them. As far as when spring starts here, it depends. Up here by Minot, we had our last major winter storm on the dates of April 30th and May 1st of this year
, not a ton of snow in that one, just really heavy winds, low temps and sticky snow that made roads ice skating rinks. I remember the late 80's when spring would come in March, having temps in the 80's and 90's a few times.