Based on daily air temperatures of 1961 to 2010 collected from 86 weather stations in Guangdong, the characteristics of anomalously lower temperatures in autumn (LTA) are analyzed with a method of mathematical and physical statistics. Then, based on the data from 1983 to 2010, the LTA effect on late rice yield is also studied by the orthogonal polynomial method. The results show that since 1997,the LTA has occurred 30% less, its intensity has got lighter and its severe cases have taken place earlier. The yield of late rice is in significantly negative correlation with the occurrence times, total number of days and frequency of severe LTA events. According to the planting system of late rice in Guangdong, the severe LTA usually occurs during the heading stage of late rice in the middle and southeast parts of Guangdong. On this basis, we suggested that the late rice planting time in the middle part of the province should be appropriately adjusted to prevent disasters.