Latitude doesn't, you're right, though the map on the site you linked shows broad-strokes correlation, and I've found it helpful if I guess imprecise in illustrating general temperature differences.

The difference in summers - cool summer vs hot summer - is a big one, and I'd suggest that it makes Boston's climate not really the same as most of northern Europe. We haven't traditionally needed air conditioning in Germany, for example, while I understand Boston and New England (the upper mid-Atlantic and New York, surely, when I lived and visited there) come to rely on it during the summer months to not just live in puddles of sweat.

You mean latitude.

You're absolutely right (we both meant that)