Honestly? The weakness of the standard small talk topics is how common and banal they are, which bores people. I recommend them because they're so easy, and the cost of boring people for a few minutes is fairly small.

But it's not ideal. For ideal you need something flippant, unimportant but also novel. Since novelty is now valued though, that means you can't be using the same thing over and over. Other people will probably have used it too, if it works, and that means its not novel.

So, the actual best ice-breaker topic? Some clever, interesting or amusing observation about something in your immediate environment that you can both look at. That adds thinking on your feet to the mix though, so is more of an intermediate level of social skill. Best to have the boring fundamentals nailed down first.

So, yeah, I'm perfectly comfortable leaning on something as dull as the weather. And it makes decent enough practice at chit chatting. But eventually picking more novel subjects that also fit the requirements is better.

The actual question would usually go something like "Hey, did you see that?"