Well the weather in Toronto is only slightly warmer (although somewhat less snow in winter). These are cool northern cities (although the summers are generally 25-30+C all through June to the end of August). Think roughly on par with New York or Chicago. Rotterdam is probably warmer than Toronto on Montreal. Vancouver is a maritime rainforest climate (the surrounding area is officially classed as a temperate rain forest) so it tends to have cooler summers but much warmer winters (generally little to no snow). Vancouver generally has the most mild winters of any Canadian city. However, none of these places are remotely tropical, so you will have to adapt to that one way or the other.