Automated methods and systems to reduce the size of time series data while maintaining outlier data points are described. The time series data may be read from a data-storage device of a physical data center. Clusters of data points of the time series data are determined. A normalcy domain of the time series data and outlier data points of the time series data is determined. The normalcy domain of the time series data comprises ranges of values associated with each clusters of data points. The outlier data points are located outside the ranges. Quantized time series data are computed from the normalcy domain. When the loss of information due to quantization is less than a limit, the quantized time series data is compressed. The time series data in the data-storage device is replaced with the compressed time series data and outlier data points.