What and when are meteor showers
Meteor showers are random events that occur at night in Animal Crossing: New Horizons. There is no way to know for sure that a meteor shower is coming, until the day it does. Sometimes random shooting stars cross your sky, so you should always keep an eye open and listen for the chime that occurs when one appears. However, during a meteor shower there will be dozens of them, starting around 19 p.m. and running until 4 a.m.
If there is one that arrives that evening, Celeste, the sister of the Blathers, will arrive in town. When you see her walking around, be ready to watch the shooting stars. She will also give you a crafting recipe for an item that can be crafted using Star Shards, the result of all that hard work (more here). These are often based on the constellations in the sky during that month, so be sure to get these recipes while you can. Once you know a meteor shower is coming, follow the next steps.
What to do during a meteor shower
All you need to do once a meteor shower starts is find a bright, open place to stand. Tap the D-pad to make sure you don't have any tools equipped, then tap the right analog stick until you look skyward. Now wait. The shooting stars should start crossing the sky and when they do, you just need to press A to wish them. Each wish you get will deliver a Star Shard to your beach the next morning. And yes, you will get Star Fragments to visit your friend's island during a meteor shower and wish it. They will appear on your own beach the next morning.
So here's our guide to the Animal Crossing: New Horizons shooting stars, explaining when meteor showers are and what to do.