1. Overview This dataset provides daily daytime and nighttime ice surface temperature (IST) over Antarctica and Greenland during 2003-2024. The data are retrieved from AMSR-E/2 brightness temperature observations using spatiotemporal random forest model. MODIS LST data was taken as the reference, and DEM, landcover, latitude, and polar day and night are included as the parameters for model construction. The mean RMSE between AMSR IST and MODIS LST are within 1 K for both ice sheets. Compared with in situ observations, the AMSR-E/2 IST is slightly less accurate than MODIS, with discrepancies within 1 K in Antarctica and 2 K in Greenland. It is the first long-term microwave IST dataset with seamless coverage, which overcome the serious data gaps issue caused by cloud cover in thermal infrared temperature data such as that from MODIS. This dataset is developed to support polar climate monitoring and the assessment of ice-sheet surface melting dynamics. 2. Data Description Data format: GeoTIFF Spatial coverage: Antarctica and Greenland Temporal coverage: 2003/01/01-2011/09/27 (AMSR-E IST), 2012/07/03-2014/12/31 (AMSR2 IST) Spatial resolution: 25 km (AMSR-E IST), 10 km (AMSR2 IST) Unit: Kelvin Temperature (K) Filename format: AMSR_LST_[orbit]_[yyyymmdd]: [orbit] has two values, namely A and D. A is for Ascending (daytime), and D is for Descending (nighttime). [yyyymmdd] represents the date format. e.g., 20030112, Year: 2003, Month: 01, Day: 12. For questions or collaboration, please contact: Zhang, Quan (zhangquanzq@nwu.edu.cn)