[Objectives]  The fall armyworm (Spodoptera frugiperda) is a notorious migratory pest that has invaded China since late 2018. Better understanding of the northward migration patterns of the pest will greatly improve the monitoring, forecasting and control of this pest. [Methods]  Based on monitoring data collected from 2019 to 2022 and historical meteorological data, the northward migration and source of migrating fall armyworm in China were analyzed using effective temperature and trajectory analysis models. [Results]  The northward migration pattern of the fall armyworm in spring and summer consisted of three primary occurrence zones and three large-scale northward migrations. The fall armyworm mainly occurred in southern China from February to April, then migrated in vast numbers into the southern regions of the Yangtze River (25°-30°N) from late April to middle May. It mainly remained in the southern regions of the Yangtze River from May to June, then migrated into the Jiang-Huai and Huang-Huai regions (30°-35°N) in June. Subsequently, it mainly remained in the Jiang-Huai and Huang-Huai regions between July and August, but continued to migrate northward of 35°N from early to middle August. There are significant annual differences in the migration patterns of the fall armyworm between 2019 and 2022 reflecting annual differences in the strength of the southward airflow and distribution of precipitation during this period. [Conclusions]  The results reveal the northward migration patterns and source of migrating fall armyworm in China, which provides a basis for monitoring this pest, obtaining early warning of outbreaks, and preventing outbreaks by controlling source populations.