Might depend on how they are constructed. A light can be seen for miles against a near black background at night.
Okay, well here’s a message to anyone thinking of sending flaming objects into the sky over tinder dry SoCal.
DON’T!
What do you make of this: http://www.openminds.tv/two-california-ufo-witnesses-10-miles-apart-describe-strange-lights/28397
For background, the distance from Trabuco Canyon in Orange County to Murrieta in Riverside County is about 15 miles as the crow flies — and there is a mountain range in between.