Vegas? Most of it is sprawl and the Strip (where few people live) is enormous hotels that are actually pretty spread out.

I agree the Montreal core is fairly walkable. Cold is generally easier to deal with than heat. There's also a large connected Underground that people use when the weather is bad.

Vegas has wide pedestrian boulevards, escalators for elevated pedestrian crossings, throughways inside casinos, and even a pair of monorails. The Strip is mostly linear and there aren't long stretches with nothing there - food, lodging, entertainment, and (of course) gambling are never more than a few dozen feet away at any point.

But I have to say, Rochester, MN - the Mayo Clinic - has to be one of the more extraordinarily walkable places I've ever been: the whole city is not only interconnected underground between apartments, parking structures, and offices but there are plentiful underground facilities as well. It amazed me to have streets so empty when I first showed up: I had no idea where everyone was! The answer is: why on earth would you go outside? :)

But it's pretty much just tourist stuff: casinos, a mixture of crappy and mostly high-end restaurants, souvenir shops, bars. I'm not sure I can think of having seen a grocery store outside of rundown convenience stores. And the transit is fragmented because most of it only runs between hotels with the same owner.

So the Strip is walkable but mostly in the same sense that a big shopping mall with tower or two of apartments is walkable.

Toronto also has extensive interconnected underground walking space. Even though the weather isn't terrible it is often bad enough that you don't want to walk outside. You can still go many places downtown on foot without being exposed to the element. Walkable doesn't necessarily require good weather year-round although that makes it easier and certainly more pleasant.

Vegas isn’t really that bad compared to Phoenix, but especially compared to anything in the Emirates. It can get hot, but not incredibly so.

To be fair, for Rochester that's an exceedingly small city core zone of a few square blocks that is interconnected like that. You're driving from where you live to that zone for 99% of the people working there.

The rest of the city is basically giant soulless suburb. I've had friends who have lived there for close to a decade now.

Though interconnection isn't common there are a number of older small cities in the Northeast with walkable, revitalized downtowns. I worked in downtown Nashua NH for a number of years and there were plenty of little restaurants, places you could run various errands, and so forth.

But the nice area was really only a handful of blocks in each direction. And beyond that you are in mostly rundown post-industrial mill town and beyond that it is very spread out.

The monorail(s) might be more useful if they were accessibly priced and not so far from the strip. At least walking through the casinos is a fairly interesting and air-conditioned experience.