Most people know these ladies only for their song, "It's Raining Men" and only by their name the Weather Girls. However, you are right that they had another name. Before they were the Weather Girls, they were a duo called Two Tons O' Fun backing up a disco and R&B singer known mononymously as Sylvester. In backing up Sylvester, they had two Top 40 hits as Two Tons O' Fun. The songs were "Dance (Disco Heat) in 1978 and "You Make Me Feel (Mighty Real)" in 1978.
The duo then released "It's Raining Men" in 1982 for which they are primarily known. They are widely cited as one-hit wonders but I guess technically if you want to split hairs their song "It's Raining Men" only reached #46 on the mainstream pop charts. To their credit, they did receive a Grammy nomination for the song, it hit #1 on the dance charts, and it has become a well-established gay anthem. So I guess put a big asterisk next to that one.