North American snow only looks to be slightly below average, after several quite high years, making it feel like it is much lower than it should be when it's actually not far off. However, adding to that, the low anomaly periods have been during what are usually the colder months. Without big snowfields to drop temperatures sharply during the longest nights, presumably that means the marginal ice areas in the Great Lakes see less or no ice formed. (Did they go into autumn with higher temperatures this year?)
The Northern Hemisphere is not far from average.