Snow drought indices are used for monitoring drought in snow-fed basins. The SZIsnow index has so far been calculated only at the continental scale, while the SMRI index has been calculated at the basin scale. Additionally, for comparing the performance of these two indices in a specific snow basin, a criterion is required. The present study introduces the Fbench ratio as a tool for comparing the SMRI and SZIsnow indices. For this purpose, in the Dez basin with an area of 23,229 square kilometers, firstly, using GLDAS, each of the SMRI and SZIsnow indices was calculated at 3, 6, and 12-month time scales over a 24-year period (1982 to 2006), and then they were compared using the Fbench criterion. The results showed that the application of snow drought index varies under different time steps. For instance, in the 3-month time step, due to the positive Fbenchsmri in 67% of months of the year and corresponding to accumulation and then melting months, the SMRI index provided a more realistic monitoring compared to SZIsnow, with a positive Fbenchszisnow increase of 17%. This is while in the 6-month time step, despite the SMRI superiority with a positive Fbenchsmri increase of 50%, compared to SZIsnow with a Fbenchsmri positivity of 8%, the SZIsnow index provided a more accurate monitoring of drought conditions. Finally, in the 12-month time step, due to the negative values of 100% for both Fbenchsmri and Fbenchszisnow, the SZIsnow index, due to its better alignment with melting months such as April, June, and July, was identified as a suitable index for hydrological drought monitoring.