I'm principle, if we knew the asteroid is going to hit a populated area (which we would in 2026), we could seriously consider deflecting it to either miss earth or hit the ocean.
Here's Scott Manley from two weeks ago.
There's nothing to do now or for the layman, though, as you said. Also, this opens the fun possibility that people could redirect an asteroid into a city, but unless they can do it secretly or deniably, nuclear weapons are probably easier.