This duo consisted of Martha Wash and Izora Rhodes, and was previously known as Two Tons o' Fun (see http://musicbrainz.org/artist/3265b337-31fd-437f-ae1a-50b9e81b7e7a.html ).
The Weather Girls, also known as Two Tons o' Fun (especially during the early portion of their career), was composed of singers Izora Armstead and Martha Wash. The duo charted several dance hits over the course of its career, with its peak in popularity having occurred in 1982, when the group released the hit song "It's Raining Men."
The rights to the name "The Weather Girls" are currently held by Dynelle Rhodes, the daughter of founding Weather Girl, Izora Armstead. Rhodes does not currently have a singing partner.