I have a lightning detector hooked up to Home Assistant. It plays a little sound on a buzzer if there are more than a handful of strikes. It's a pretty reliable warning a storm is coming, and my partner (who is a prolific runner) knows not to go out for a run or to turn around.

I've also done sciencey type testing work outdoors, the ranges all had lightning detectors and all work would stop and you had to take shelter if lightning was detected. Mostly wide open space so getting struck by lightning was a serious danger.

A camera! The 2.5mm TRS remote trigger jack just needs one of the pins connected to the sleeve to trigger the camera, very easy to do with an optocoupler or even relay.

Usually, lightning detection is necessary for regulatory compliance. Facilities with pools need to remove patrons to prevent risk of electrocution, summer camps need to move people to enclosed shelters, as with golf courses, construction sites, beaches/waterfronts, etc.