Abstract:In the winter of 2024/2025, the mean temperature in China was 0.4℃ higher than normal with significant intra-seasonal variations. Average precipitation was 41.1% lower than normal, and the regions south of the Yangtze River experienced persistently less precipitation. Atmospheric circulation patterns in the mid-to-high latitudes over Eurasia have shown staged differences in this winter. In December 2024, the Arctic Oscillation was in a negative phase and the East Asian trough and Siberian high were stronger than usual. All the three got weakened in January 2025 and then strengthened again in February. Especially in February, the negative phase of the Arctic Oscillation reached the strongest stage of this winter while the activity of Eurasian blocking high was significantly enhanced. These factors collectively triggered an obvious shift in the temperature of China from warmer to colder conditions. In the 2024/2025 winter, the low-latitude atmosphere responded significantly to the La Nina-type sea surface temperature anomalies in the equatorial central-eastern Pacific. Persistent cyclonic circulation anomalies dominated the lower troposphere from the Philippines to the South China Sea, while the regions south of the Yangtze River in China remained consistently influenced by northerly wind anomalies. Coupled with persistently weak activity of the India-Burma trough, the influences of multiple circulation conditions led to sustained moisture transport deficits and significantly reduced precipitation in eastern China, particularly in the southern part.