Yes, if we are talking about “averages.” This doesn’t mean we don’t have cold winters or still a lot of ice, but we have in general slightly later starts and earlier ice out for many bodies of water. Like mnfisherman18 said, it isn’t a ton…but just enough to notice if you have been fishing long enough.
We routinely participated in the WI Gun Season the weekend before Thanksgiving and harvested deer on Saturday, then would start our ice fishing that Sunday morning (along with a lot of other people) on 4-5″ of solid ice near Pool 4. I cannot remember many years of my adolescence or even early adulthood where this wasn’t our routine. In the last 10 years I think I’ve now been able to do that once, twice if you count shoving out in a flat bottom boat cracking ice as we went in spots just to say we were out.
I’d say in my lifetime safe ice has shifted probably 2 weeks later on average with some outliers sprinkled in. The other big difference I’ve noticed is more “thaw” events in the middle of winter. I do not remember nearly as many 40 degree January days years ago as we have now. Temperature swings are a bit more extreme for sure. I think we are likely to have more slush problems with these thaws and big snow storms that pop up in coming years.
Ask snowmobilers who live from the Metro southward just how often they’ve had a lengthy season in their home areas in the last 10 years…it’s maybe a year or two at best. Years ago snowmobiles sat at bars, school parking lots, restaurants, etc. starting around Christmas right through mid-March in SE Minnesota and Western WI. Now when we get a fresh 6″ of snow following a cold spell people are anxiously waiting for a trail to open with muddy corners debating taking off work to go riding for a couple days while they can.