Displacement is not a new phenomenon in Yemen, but the number of people fleeing violence increased sharply in 2015, when a coalition of foreign countries intervened in the country’s civil war. The ensuing humanitarian and displacement crisis has shown no signs of abating since.

As the country’s conflict entered its sixth year in 2020, clashes between Yemen’s internationally recognised government and Ansar Allah, also known as the Houthi movement, triggered 143,000 new displacements. Many were the result of indiscriminate attacks and the shelling of densely populated areas. Hostilities intensified in hotspots such as the governorates of Hodeidah and Taizz, and new frontlines emerged.

The country’s humanitarian crisis was aggravated further by devastating floods and storms during two intense rainy seasons between February and September 2020. Disasters triggered 223,000 new displacements during the year, the highest figure on record for Yemen. The floods caused widespread destruction, killed hundreds of people and forced thousands of IDPs to flee again, highlighting how the impacts of disasters and conflict overlap in the country.


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The conflict has its roots in long-standing political, economic and social tensions and divisions. Violence and displacement affected northern parts of the country in 2004, but the situation worsened considerably in 2011 when President Ali Abdullah Saleh was ousted after 22 years of rule in the context of the Arab Spring. That year, widespread political unrest, instability and violence triggered about 175,000 new displacements. A transitional government led by the vice-president, Abdrabbuh Mansur Hadi, took office in 2012 and a national dialogue process in the following years failed to stabilize the political situation.

In the South, tribal militias and extremist groups affiliated with AQAP took advantage of social divisions to morph into organised structures capable of controlling extensive territories. In the north, Ansar Allah, a Zaidi Shia political and armed group also known as the Houthi movement, extended its influence across the country. Direct clashes between Ansar Allah and government forces grew in intensity with Ansar Allah taking control of the capital Sana’s in September 2014.

The situation reached a peak in 2015 as Ansar Allah continued to move south, reaching the outskirts of Aden. In response, a coalition of Arab states led by the Kingdom of Saudi Arabia launched a military campaign in March to defend and reinstate the ousted government. This opened a new chapter in Yemen’s war. The Saudi-led coalition used heavy weapons and airstrikes that destroyed housing and infrastructure on a broad scale. Forces loyal to the internationally recognised government secured their positions in the south. Supported by the UAE, the Southern Transitional Council (STC) emerged in 2017 as the first armed opposition group on Hadi’s side, and a power-sharing deal between both political forces was signed in November 2019.

Renewed tensions surfaced in 2020, however, when the STC declared self-rule in southern governorates. This aggravated social divisions and led to new attacks that displaced many people in what had been relatively safe areas, such as Abyan governorate. Escalating violence in Marib governorate, the last government stronghold in the north and a refuge for more than 770,000 IDPs, triggered new displacements and worsened security and living conditions for those already displaced. More than 23 displacement sites had to be evacuated when the violence flared in January, forcing people to move again to new sites unable to provide for their basic needs. Airstrikes, shelling and an escalation in fighting also triggered significant waves of displacement in Al Jawf governorate.  As frontlines shifted and civilians were caught in the crossfire, many IDPs were forced to move various times to escape the violence.

Sudden-onset disasters also strike Yemen every year, particularly during the rainy season. In 2020, floods displaced more people than conflict and violence with 223,000 new displacements recorded, the highest figure on record for the country.

Displacement patterns in Yemen have fluctuated according to shifts in the frontlines of the conflict as entire families flee and return with the ebb and flow of violence. Most displacement before 2014 was concentrated in the northern Sa’ada governorate, but the largest movements took place in 2015 when displacement was reported in every governorate. More than 2.5 million people were living in displacement across the country by the end of the year.

In 2016, a relative stabilisation of the conflict, especially in the South, led to a considerable reduction in the number of IDPs. More than a million people were believed to have returned home. Between 2017 and 2018, the highest numbers of displacements took place in the west especially from areas around Hodeida.

Marib and Al Jawf governorates, which had largely been spared from the conflict, became important destinations for IDPs. Between them they were hosting 919,000 at the end of 2019. In January 2020, however, Ansar Allah launched an offensive against the coalition’s positions in Marib. This triggered more than 60,000 new and secondary displacements in the two governorates in the six first months of the year and worsened security and living conditions for those already displaced. More than 23 displacement sites had to be evacuated when the violence flared, forcing people to move again to new sites unable to provide for their basic needs.

Unlike other major conflicts in the region, the situation in Yemen has not triggered large-scale cross-border movements. Many more people may have wanted to flee, but a range of physical, economic and social obstacles will have prevented them from doing so. Restrictive migration policies and the high cost of travel in particular have contributed to widespread forced immobility, increasing internal displacement.  

Because of their high population density and the prevalence of informal settlements, urban areas are particularly at flood displacement risk. Many IDPs in Sana’a city are renting accommodation in flood-prone areas rather than safer neighbourhoods, which are up to four times more expensive. The 2020 floods destroyed most of these settlements or rendered them uninhabitable, leaving families homeless again and in many cases living in the open.

The humanitarian situation in Yemen is considered the most acute in the world with around 80 per cent of the population currently in need of humanitarian assistance. Around 3.6 million people, or about 12 per cent of the population, were internally displaced as of the end of 2020, many of them since 2015. The situation is becoming increasingly dire as compounding crises threaten the lives, security and livelihoods of local populations.

The bombings disrupted markets, education and health services and crippled infrastructure vital for the provision of goods. If poverty and malnutrition were already high before 2014, the rapid escalation of violence only served to make the situation worse. The overlapping impacts of conflict, disasters and the Covid-19 pandemic also weakened Yemen’s already precarious economic situation, further worsening living conditions for millions of people. The country’s humanitarian crisis was aggravated further by devastating floods and storms during two intense rainy seasons in 2020.

IDPs face a wide range of protection needs and vulnerabilities, including a lack of shelter, security and livelihood options, gender-based violence, loss of documentation, food insecurity and limited access to healthcare, education, water and sanitation. Children account for half of the country's IDPs, and they are exposed to various forms of abuse, including recruitment into non-state armed groups and early marriage.

The vast majority of Yemen’s IDPs live in makeshift settlements, which puts them at high risk of secondary displacement when disasters strike. Many lost their shelters, property and food stocks to the rains and floods in 2020. IDPs forced to flee again accounted for many of the new displacements recorded in the Abs district of Hajjah in late April.

Returning may mean going back to a damaged or destroyed house. Some people have even returned to home areas near the frontlines because of the high costs associated with their displacement. IDPs meanwhile face high levels of food insecurity and few services and livelihood opportunities.  More than a third live in vulnerable shelters, and many are displaced again by flash floods, evictions or violence as a result. The Covid-19 pandemic has heightened these vulnerabilities, added to movement restrictions and further decreased employment opportunities.

Although challenging to implement, ceasefires such as the Stockholm agreement of 2018 have reduced displacement. A lasting peace is essential to address Yemen’s humanitarian crisis and may enable  IDPs, who in some cases have been displaced for years, to achieve sustainable solutions.

Yemen adopted a national policy on internal displacement in 2013 that underscores the need to protect and assist IDPs. It covers conflict and disasters, and is intended to prevent displacement and create mechanisms to cope with it in the future. It contains specific support for IDPs and other affected communities by making provisions in the areas of housing, employment, training and recovery. It also sets out clear responsibilities and focal point institutions.

The policy, however, remains largely unimplemented, the result of significant shortfalls in terms of resources and capacities, and the escalation of conflict since 2014, which had led to a deepening divide between the country’s different administrations.

Latest Figure Analysis

Latest GRID figures analysis


Based on multiple sources, these estimates include both IDPs and returnees to Afghanistan, primarily from Iran and Pakistan. Some returnees have been included in our stock figure based on contextual evidence from partners in the field.

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