"On July 31, 2025, the World Meteorological Organization certified a new lightning record. It’s for the world’s longest lightning flash, an incredible 829 km (515 miles) in a notorious storm hotspot in the United States. The flash happened in 2017. Watch in the player above or on YouTube."
Youtube world’s longest lightning flash
So, if there is any chance of lighting within 500 miles you may not be in danger, but you do have an excuse to put away your tools and go inside for the day. ("Sorry honey, weatherman says thunderstorms within 400 miles, time to come inside!")
WOW! That was some flash! With all of our rain this season, we haven’t really had any thunder & lightening shows - they’ve all just been drenching soakers, which is better, I guess.