We present a comparison of statistical and principal component analyses (PCA) for reducing the amount of near‐field data required as an input to a time‐domain spherical‐multipole near‐to‐far‐field transformation. Such transformations are necessary for finite‐difference time‐domain (FDTD) simulations that typically only model the near‐field. The authors demonstrate their approach for the case of far‐fields scattered by a dielectric sphere. For a threshold value of 106, the PCA technique reduced the data required by 32%, using 12 components. A similar compression was achieved with statistical analysis, when the threshold is set at 10−7σ. Their work shows that the proposed statistical compression is preferable because it has simpler implementation and low‐cost processing, when implemented together with the NFF transformation code.