Sometimes on a hot, humid day, we see lightning off in the distance. If we're out on a trail or camping in the evening, it's even brighter. It seems to be traveling in almost a sideways motion. We don't see it hit the ground. We don't hear thunder, and it doesn't rain.
I've been told this lightning is just happening because of the temperature and humidity, and possibly a cold front coming through, but there's no storm attached. They call it “heat lightning.” Is that a real thing?