After Power Rangers in Space (1998), Jason Narvy, Skull, decided to go back to school. So they wrote him out of the series. That's why he only appeared in the first episode.
This is the only series in Power Rangers where a former villain from a previous segment becomes a Ranger.
Reggie Rolle (Damon Henderson) and Amy Miller (Trakeena) fell in love during filming and later married. They would later divorce.
This season had the highest ratings for any Power Rangers opening, yet Digimon: Digital Monsters (1999) was more promoted, thus ratings fell.
Mid-way through the season Pink Ranger actress Valerie Vernon was diagnosed with leukemia and was replaced by Melody Perkins (Karone/Astronema) for almost the remainder of the series.