Abstract: To analyze the occurrence pattern of abnormal low-temperature events during winters in the Middle Route Project of South-to-North Water Diversion, the Zhuozhou meteorological station was selected as a case study.The station is located at the northernmost end of the open channel section of the main canal and experiences relatively low winter temperatures and severe ice conditions.Utilizing the daily average temperature data of Zhuozhou Station from 1981 to 2021, winter abnormal low-temperature events were identified and classified using the standard deviation threshold method.A statistical analysis was performed to assess the frequency variation of these events over the past 41 years.The results indicated that: ① The daily average temperature at Zhuozhou Station was near 0 ℃ in December, gradually dropping thereafter.It reached the yearly low from late December to mid-January, averaging around -4 ℃.Subsequently, temperatures rose, returning to above 0 ℃ by mid-February.② During 1981 to 2021, Zhuozhou Station experienced 31 abnormal low-temperature events, totaling 251 days.The 1980s had the highest frequency, followed by the 2000s and 2010s, with the 1990s having the lowest frequency.There was a decline in event frequency over time.③ Among the winter months, January had the highest frequency and longest average occurrence days, followed by December, with the lowest frequency and shortest average occurrence days in February.Abnormal low-temperature events in winter mainly occurred from late December to early January and mid to late January.④ From 1981 to 2021, Zhuozhou Station has encountered 11 Grade 1, 5 Grade 2, and 15 Grade 3 abnormal low-temperature events during winter.Grade 1 and Grade 3 events were the most in January, while Grade 2 events were the least in that month.From the formal water supply of Middle Route Project of the South-to-North Water Diversion to 2021, there were three Grade 3 abnormal low-temperature events in winter, which had a limited impact on water diversion during the glacial period.These research findings can serve as a reference for guiding water transportation scheduling and preventing ice-related disasters in the Middle Route Project of South-to-North Water Diversion.