The Palmer Drought Severity Index (PDSI) ranges from −10 to 10 and is used for monitoring drought extent and severity. PDSI is a monthly global gridded data set with partial global coverage from 1850 through 1947 and full global coverage from 1948 through 2018. PDSI updates are infrequent. We present a method to extend PDSI using Global Land Data Assimilation System (GLDAS) data. We provide an updated dataset and code for the method. We discuss the accuracy and bias of the method for various regions. We have high accuracy, with 99.5% of the globe exhibiting RMSE values less than 1. Globally our method is unbiased with an average ME of approximately 0. Some regions have slight biases with dryer and wetter regions showing a slight negative and positive biases, respectively. Prediction errors exhibits spatial trends with the highest errors in areas with extreme climate.

帕尔默干旱严重程度指数 (PDSI) 范围从 -10 到 10，用于监测干旱程度和严重程度。PDSI 是一个月度全球网格数据集，从 1850 年到 1947 年部分覆盖全球，从 1948 年到 2018 年完全覆盖全球。PDSI 更新很少。我们提出了一种使用全球土地数据同化系统 (GLDAS) 数据扩展 PDSI 的方法。我们为该方法提供了更新的数据集和代码。我们讨论了该方法在各个区域的准确性和偏差。我们有很高的准确度，全球 99.5% 的 RMSE 值小于 1。在全球范围内，我们的方法是无偏的，平均 ME 约为 0。一些地区有轻微的偏差，干燥和潮湿的地区分别显示出轻微的负偏差和正偏差.