A rain tight connector may include a connector body, a gland nut coupled to the connector body, and a compression ring. A locknut is coupled to the connector body on the end portion thereof opposite to the gland nut. The compression ring includes a central portion and first and second coaxial end portions. The central portion defines an annular stop. A locking unit with a plurality of locking teeth is provided in the present invention to further secure the metal tube. More specifically, the locking unit can be inserted into the compressing ring to strengthen its structure to securely hole the metal tube