Precipitation (P), air temperature (T), soil water content (SWC) and soil temperature (ST) are important factors affecting agroecosystems, and accurately depicting their spatio-temporal characteristics is the basis for recognizing and understanding the hydrothermal interactions, and for developing strategies for regional agricultural sustainable development. However, these related works are considerably constrained by the sparse and short-duration in-situ observations. In order to characterize the spatiotemporal changes of these factors and their interrelationships, the temporal changing trends, mutability characteristics, and spatial patterns of P, T, SWC and ST were mapped and analyzed using Sen's slope, Mann-Kendall test based on ERA5-Land reanalysis data in the North China Plain during 1953 and 2022. The relationships among these factors were then explored by using the Spearman's correlation coefficient. The results show that: (1) the annual total precipitation has fluctuated between 509.80 and 1393.05 mm over the past 70 years, with a change rate of -38.31 mm/10 a and abrupt change year around 1988 in the North China Plain, while the fastest decrease rate of precipitation was observed in summer; (2) The mean annual temperature fluctuated between 12.11 and 15.35℃, with a change rate of 0.27℃/10 a, the year of abrupt change was around 1996, while the fastest warming rate occurred in winter; (3) The distribution of P and T was characterized by higher in the south and lower in the north, with a faster rate of decrease in P and slower rate of T in the southwest of the North China Plain, while the opposite trend was found in the northwest. SWC showed a decreasing trend; (4) The SWC of 100-289 cm layer showed the largest rate of change and gradually increased with time, and the seasonal variations of SWC in the four soil layers were different; (5) ST showed an increasing trend and the warming rate became faster with time, and the 0-7 cm layer had the fastest rate of warming. Soil warming was the largest in spring and the smallest in autumn; (6) The magnitude of the SWC decrease increased with depth, the magnitude of the ST elevation decreased with depth. The effects of soil depth on SWC and ST were opposite, and the turning point of SWC was nearly 20 years earlier than that of ST. The spatial distribution of ST and SWC was higher in the south and lower in the north, and the variability was larger in the northwest and smaller in the southeast. P and SWC, T and ST were positively correlated, while SWC and T, P and ST were negatively correlated. The correlation of SWC with T and P, and ST with T and P decreased with soil depths. The North China Plain shows a dryer and warmer climate and the agriculture is vulnerable to future climate change. The study can improve our understandings of the hydrothermal change process in the North China Plain and provide a scientific basis for policy decisions on the sustainable agricultural development within this region.