Gaza Floods: Why Gaza Floods in Winter and What It Means for Displaced Families

A Gaza flood does not take an extreme storm. Gaza floods most winters because rain falls in short, heavy bursts on low, sandy coastal ground where drains and sewage pumps no longer work, and because most people now live in tents or damaged buildings that cannot keep water out.

The last rainy season showed the scale. The UN humanitarian office (OCHA) reported that storms in December 2025 affected some 65,000 households, and in January 2026 aid agencies estimated that nearly 795,000 people were sheltering in flood-prone displacement sites. As of late September 2026, with the next rains weeks away, 451 sites hosting about 464,000 people were classed as being at high risk of flooding.

Why does Gaza flood? The geography

Gaza is a narrow strip of coastal plain on the Mediterranean. Almost all of its rain falls between November and March, often in a handful of storms (our guide to Gaza's winter weather has the monthly averages). When that rain arrives, it runs toward the lowest ground.

OCHA's reports name two features again and again: "poor drainage and low-lying terrain." Coastal sites are the worst placed. In January 2026 OCHA described families pitching makeshift shelters "on low, sandy land vulnerable to flooding from both rainfall and the sea", and in late December 2025 it reported seawater inundating tents in the Al Mawasi area of Khan Younis.

Gaza also has a natural watercourse, Wadi Gaza, which crosses the middle of the strip. Winter runoff from the Hebron hills historically flowed through it to coastal wetlands and the sea, although upstream diversion has reduced that flow and the valley has long been used for dumping sewage and waste, Euronews reported in 2023. Flood-risk mapping by the International Organization for Migration (IOM) and Acacia Water uses terrain depressions, elevation, drainage paths and areas that have flooded before to predict where water will collect.

Broken drains and sewage systems

A city sheds rainwater through storm drains, pumping stations and holding lagoons. Gaza's were fragile before the current war. In December 2013 a winter storm displaced about 10,000 people in Gaza after heavy flooding, and OCHA reported that pumping stations and lagoons overflowed during a fuel and electricity crisis.

Today the system is in far worse condition. In September 2026 OCHA warned that "the inability to operate and maintain sewage and stormwater drainage systems poses severe flooding and public health risks" for hundreds of thousands of displaced people, citing restrictions on the entry of equipment, generators and spare parts and a funding gap for fuel.

Repairs are hard to make. The Shelter and Site Management clusters reported in January 2026 that drainage pumps and pipes were among the items restricted from entering Gaza as "dual-use" goods, leaving aid groups with improvised fixes. Before the December 2025 storms, partners handed out empty flour sacks to be filled with sand and used as sandbags.

Tents and makeshift shelters

Most of Gaza's population is displaced, and a tent pitched on bare sand has no floor, no foundations and no gutter. OCHA described what the December 2025 storms did: "Tents were blown away or damaged, homes collapsed under storm conditions, and personal belongings were soaked. In several locations, entire displacement sites were flooded."

Families who shelter in damaged buildings to escape the water face a different danger. Gaza's Ministry of Health reported 25 deaths from building collapses in bad weather between mid-December 2025 and mid-January 2026, according to OCHA. Safer ground is scarce: shelter agencies say a lack of available land prevents families from relocating. Our guide to displacement in Gaza explains where people are living and why.

What flooding does to people's health

Floodwater in Gaza is rarely just rain. On 11 December 2025 OCHA said heavy rains had increased health risks, "including hypothermia among babies and illnesses linked to overflowing sewage."

• Water-borne disease: in January 2026 Save the Children warned that rainwater mixing with sewage exposed children to hepatitis, diarrhea and gastroenteritis.
• Cold: Gaza's Ministry of Health reported that seven children died of hypothermia between 1 December 2025 and 14 January 2026. For the winter as a whole, at least 11 children were reported to have died from hypothermia, according to UNICEF.
• Respiratory infections: these made up more than half of the communicable-disease consultations recorded by health partners in the second half of December 2025.
• Lost essentials: soaked bedding, clothes, food and documents, and flooded latrines. In mid-January 2026 one period of storms left 253 water and sanitation facilities out of use.

Recent Gaza flood events: a dated record

These entries come from OCHA, UNRWA, the Shelter and Site Management clusters and the EU's humanitarian office, mostly as compiled on ReliefWeb. Aid agencies say the true totals are higher, because only a sample of sites could be surveyed.

• 25 November 2024: overnight downpours flooded tent camps across Gaza, and UNRWA warned that half a million people were at risk in areas hit by flooding.
• 14 November 2025: heavy rain caused severe flooding, especially in Gaza city and northern Gaza, affecting more than 13,000 families and destroying thousands of tents.
• 25 November 2025: further rain affected 32 designated emergency shelters and more than 3,000 people, most of them in Khan Younis and Deir al Balah.
• 11 December 2025: aid teams processed over 160 flooding alerts in a single morning. The Shelter Cluster estimated that the weather to that point had affected more than 740,000 people across 715 displacement sites.
• 16 December 2025: 132 flood incidents were reported in one day, 91 of them in Khan Younis. At 22 sites, 821 families were left with no shelter at all.
• From 26 December 2025: rainstorms brought flash flooding to low-lying and coastal areas, and seawater again entered tents in Al Mawasi.
• Mid-January 2026: 106 sites reported storm damage, with about 19,230 people affected, seven deaths, 34 injuries and 3,455 tents or shelters destroyed or badly damaged.
• From 23 February 2026: heavy rain flooded tents in Al Mawasi, where several families had to be rescued, and parts of Gaza city.

Who is at risk this winter?

An IOM and Site Management Cluster analysis dated 1 March 2026 found that 912 of 1,474 known displacement sites, hosting about 987,000 people, lay in predicted flood-risk zones, with the largest number in Khan Younis.

The most recent figures we could verify are from OCHA's report of 25 September 2026. The Site Management Cluster was inspecting 451 sites judged to be at high risk of flooding, home to an estimated 464,402 people, to see whether flood-prevention work was feasible or whether families would need help to move. OCHA said funding shortfalls and restrictions were "severely constraining preparations for the rainy season", with available stocks covering only a fraction of the need.

How to help before the rain

Flood protection only works if it is in place before the first storm: sealed tents and tarpaulins, raised bedding, cleared drains and, where possible, a move to higher ground. Our guide to Gaza winter relief explains what that support includes and how to judge a winter appeal.

Fight for Palestine raises funds for emergency aid delivered through local partner teams, including shelter and winter items, clean water and food. You can donate here. The flood figures on this page describe Gaza as a whole, not our own work.