The S-PolKa system was deployed in the Maldives for 4.5 months during the Dynamics of the Madden Julian Oscillation (DYNAMO) field campaign. The humidity retrievals showed a large spatial and temporal variability that was also reflected in the sounding data. The S-PolKa retrieved humidity is verified against the 3 hourly sounding data using only data that was very close in time and space in order to minimize the impact of the natural variability and the sampling differences. The comparison indicated the radar humidity retrievals were unbiased in comparison to the sounding measurements. The retrievals are then used to investigate the variability of the humidity in the tropical DYNAMO domain. Because the radar retrievals cover a large spatial scale compared to soundings, the environmental mean and standard deviation of humidity lower troposphere can be estimated. This information is important to numerical modeling and process studies.