This dataset was co-supported by the Guangdong Major Project of Basic and Applied Basic Research (2021B0301030007), National Key Research and Development Program of China (2024YFF0809000), and National Key Scientific and Technological Infrastructure project “Earth System Science Numerical Simulator Facility” (EarthLab). field observations and climate: Summary of CERN field observations and the growing-season average climate conditions for each station, including station names, geographic coordinates, number of sites and records, and growing-season average surface air temperature (T), precipitation (Pr), and relative humidity (RH). site-level trend: CERN site-level long-term trends of phenological stage dates and GSLs. station phenology and GDD: CERN station-level multi-year averages of phenological stage dates and GSLs and its GDD station GSL and T: CERN station-level GSL and growing-season average surface air temperature percentage of sites for std distribution: Percentages of standard deviations (std) of key phenological stages and GSLs falling into corresponding intervals (days) for wheat, maize, rice, and soybean.