Lightning isn't just a result of thunderstorms, ya know. Sometimes you even see it around volcanic eruptions: https://en.wikipedia.org/wiki/Volcanic_lightning. And sometimes you see it at Meetups! That's right. We're doing lightning talks! We're going to target 5 minutes per talk to give everyone a chance "on stage", but we engineers tend to go over estimates by 20%. You can bring slides--we'll have a projector--but don't think that's a requirement. You could open a terminal to show off a cool new tool. You could demo some application you built. You could even tell us a little more about volcanic lightning. I know you clicked that link.
If you know you want to give a talk, comment down below. If you don't have a topic, no worries; you can decide one minute before the last person finishes. And if you just don't want to talk, but you want to learn a little about a lot, that's fine, too, but I recommend giving it a try. None of us is as smart as all of us, and everyone has something they can share for a couple minutes.