Abstract: Based on the observation data of winter wheat from 1990 to 2018 and the meteorological data of 30 agrometeorological observation stations in Henan province, the occurrence time and intensity of dry-hot wind in the past 29 years were determined according to QX/T 82-2019, the occurrence law of dry-hot wind in Henan province and its relationship with winter wheat flowering period were analyzed by numerical analysis method. The results showed that the annual type of dry-hot wind in Henan province increased first and then decreased in the past 29 years, and the dry-hot wind process was a decreasing trend, and the annual types and processes of dry-hot wind were mainly occurred in 2000-2009. The high incidence area of dry-hot wind in Henan province is mainly concentrated in the northern and central regions of Henan province, and some parts in the western and southwestern. The main reasons for the increase of the annual type in 2000-2009 are the increasing of the heavy dry-hot wind process and the increase of the occurrence area of dry-hot wind. The earliest occurrence date of dry-hot air was on the 144th day of Julian day, and in recent 29 years there was a tendency to postpone the local occurrence dates of most parts of central Henan, western Henan and southern Henan, and the trend of other regions was in advance, and the overall trend in different years was delayed from west to east and from south to northeast. The average date of flowering period was the 126th days of Julian day, and the flowering date of winter wheat in Henan province was gradually advanced from north to south in the past 29 years. The number of days in most areas of Henan province was dominated by the trend of prolongation, and the earliest time change trend of dry-hot air was significantly correlated with the change trend of dry-hot air and flowering interval. The change trend of flowering period was significantly related to the process of heavy dry-hot wind.

Key words: dry-hot wind, winter wheat, flowering period, interval day