Predator's origins are unknown, and for the sake of man, it would be best that it
stays unknown.
[clearing throat]
Ehrmm, ermmm, yes, anyway, the Predator's origin, otherwise known as the Yautja, are highly unknown. Most likely from another galaxy, though, are theories of a supposed 'homeworld,' like what Shadow said above. Because of what we know from past experiences with the Yautja, their sun may interfere with their vision, giving them the 'right' kind of vision (like us humans, giving them the ability to see "clearly"). And as stated, they hunt in the hottest of seasons, giving the high possibility of their planet being in secluded jungles, with temperatures high above human limits.
Jungles where only human imagination can go. A planet that only extraterrestrial life forms can go. "It's clear that...
Quote from Scary Movie 4
"We're totally f*cked."
"To me, everyone is crazy. The ones in the mental house just got caught."