I didn't think it would be possible but I reached 100% on my town's beauty meter! Now that I have I'm a little disappointed. Maybe in future updates there could be fireworks or something, like when you add a new feature. Thanks.

I think it is a good way to let us know that we have finished cleaning everything up for the moment.

There ARE fireworks. They go off in your head the next morning when your town beauty drops to 87%. (I just picked a number at random. I don't have a clue how far it drops. If my town gets to 96% on a given day, I stop paying attention. You can get back to 100%, though!)

Even though the beauty meter shows 100% in my game I'm still finding clumps of long grass so it can't be quite at the maximum.