Abstract: The long-term variation features of the spring temperature and extreme temperature indexes in Northeast China are analyzed and their contemporaneous and time-lagged relationships with the Arctic Oscillation (AO) index are investigated by using the daily temperature data from 1957 to 2000 at 32 stations in Northeast China. The results show that the spring daily temperature anomaly generally increases from higher latitudes to lower latitudes and from the east to the west, and it has been increasing in the recent years. The cold days and cold nights in spring exhibit decreasing tendencies, while the warm days and warm nights increasing ones. There is a closely positive correlation between the spring temperature in Northeast China and the spring AO index on yearly time scale. Besides, AO index and extreme temperature indexes have the same period and abrupt change date.

Key words: Northeast China, temperature in spring, the anomaly of daily temperature, skewness coefficient, extreme temperature index, Arctic oscillation index