IOM Yemen DTM’s Flow Monitoring Registry (FMR) monitors migrant arrival on the southern coastal border and Yemeni return locations on Yemen's northern border with the Kingdom of Saudi Arabia (KSA). Enumerators placed at Flow Monitoring Points (FMPs) record arrivals of migrants and returning Yemeni nationals in order to identify different patterns of migration, and to provide quantitative estimates to help define the population of irregular migrants entering the country. FMR is not representative of all flows in Yemen and should be understood as only indicative of the individuals recorded at FMPs during the time frame indicated. Access constraints limit the ability to collect data at some migrant arrival points.
In December 2021, IOM Yemen DTM estimates that 3,690 migrants entered Yemen, compared to 3,622 migrants in November 2021. In addition, it is estimated that 5,836 Yemeni returns from KSA during the month of December 2021, compared to 5,802 in November and 6,158 Yemenis in October 2021. During the period between 1 January and 31 December 2021, an estimated 27,693 migrants and 27,845 Yemenis arrived in Yemen.