I'm sure it only gets better when the weather cooperates. It seemed like late winter in most of the Canadian ports.
Of course, weather is never a guarantee anywhere but it stands to reason there is a better chance of warmer weather for a Canada/New England cruise the later in the season you go. The prices reflect that.
I understand the repositioning cruises are always start/end of season but that is one of the downsides when booking them. Not to say that some times one won't get lucky and have better weather.
I wish HAL could control the weather and we always had sunny days, not too hot and not too cold.