The present disclosure relates to spectral analysis in wireless current sensors. For example, a wireless current sensor (WCS) includes current transformer windings that harvest electrical energy from a power line and allow the WCS to obtain current measurements of the power line. The WCS includes a processor that obtains the current measurements of the power line via the current transformer windings. The processor generates a frequency domain representation of the current on the power line using the current measurements. The processor sends a wireless signal indicating results from the frequency domain representation to an intelligent electronic device (IED) that monitors the power line to allow the TED to analyze the results for anomalies.