Systems, methods and software can be used for processing microseismic data from a subterranean region. In some aspects, groupings of data points are identified. The data points are based on microseismic data from a subterranean region. The identification of the groupings is constrained such that each grouping includes at least a minimum number of the data points, and such that the data points in each grouping have at most a maximum extent of variation. In some instances, a histogram of the data points is generated, and each of the identified groupings corresponds to a bin in the histogram.