DC Stabilized Discharges (DCSD) was generated in atmospheric pressure argon for a pin to plate. In this paper, discharge with a flowing argon gas into the air (plasma Source) is investigated by optical emission spectroscopy technique. The emission spectra of excited species of atomic-hydrogen, N₂ and Ar were observed and measured. The rotational and vibrational temperatures of the discharge were measured by comparing modelled optical emission spectra with masured spectra from the discharge by using several different vibrational bands of the 2nd positive system (SPS) of N₂ ( N₂[C ³Π_u] → N₂[B ³Π_g]). The optical characteristics of the discharge shown that the DCSD was found to be non-equilibrium with rotational temperature (T_r) of 1087 K and vibrational temperature (T_v) of 1661 K.  Boltzmann plot method has been applied to estimate the electronic excitation temperature which  was found to be 1.36 eV and 1.1 eV for discharges with argon flow rates of 1.0 SLM & 0.5 SLM respectively. This finding proved the strong non-equilibrium nature of the discharge conditions of the current work.