Hainan's Record Deluge Forces 55,000 to Evacuate as Reservoirs Open

Wuzhishan Breaks a 68-Year Rainfall Record as Hainan's Interior Goes Under

Wuzhishan, a mountainous city in the centre of Hainan, recorded 616.2 millimetres of rain in the 24 hours to the morning of September 14 - the heaviest single-day total in its urban area since meteorological records began there in 1958, according to the city's media centre and the Hainan Provincial Meteorological Service.

The figure was not an isolated spike. A day earlier, Wuzhishan logged 429.9 millimetres, enough to meet the "exceptionally heavy rainstorm" threshold and break the local daily record, CCTV News reported. Across a wider band of the island's interior, rainfall exceeded 700 millimetres at six locations in Baoting Li and Miao Autonomous County, Qiongzhong Li and Miao Autonomous County and Wuzhishan between 8am on September 11 and 2pm on September 14. The highest total, 912.9 millimetres, fell in Xiangshui township in Baoting.

The damage arrived with the water. Flash floods ruptured gas and water pipelines at multiple points in Wuzhishan, forcing local utilities to suspend both supplies across the city on the morning of September 14. Firefighters rescued 14 people trapped in a two-storey farmhouse and nearby small homes, using an excavator to move them to safety in about an hour, the city's fire brigade said. In Baoting, crews pulled four people from a pickup truck and an electric bicycle stuck in floodwater. No casualties had been reported in Wuzhishan as of the afternoon of September 14.

"I see flooding in many parts of the city," a Wuzhishan resident surnamed Lin told China Daily. "It's been pouring for days. Many areas have lost water and power. Cars are submerged on the roads, and some have been washed away."

How a Dying Tropical Depression Met a Cold Front

The mechanism behind the deluge was, in meteorological terms, unremarkable - and that is precisely what made it dangerous. A tropical depression over the South China Sea made landfall in Vietnam on the evening of September 13 and was not expected to develop into a typhoon. But the remnant circulation of that weakened system, colliding with cold air pushing south, produced days of torrential rain over central, western and southern Hainan, with exceptionally heavy downpours in some areas, according to CCTV News.

Authorities layered warnings as the rain persisted. The Ministry of Water Resources and the China Meteorological Administration jointly issued a blue alert for flash floods in southeastern Hainan on Saturday, alongside a yellow alert for geological disaster risk. By noon on September 14, Hainan had raised that geological warning to its highest level, telling residents that the risk of rain-triggered landslides would be "very high" over the following 24 hours in areas including Tongshi township in Wuzhishan and Xiangshui township in Baoting. An orange alert covering six cities and counties, among them Wuzhishan, Qionghai and Wanning, remained in force.

On the rainfall side, the Hainan Meteorological Service held a Level II rainstorm warning until 9:40am on September 14, then downgraded it to Level III at 4pm. It forecast 100 to 150 millimetres of further accumulation for eight cities and counties from 10am on September 14 to 8am on September 15, with isolated areas receiving more than 250 millimetres.

The Evacuation Curve: 31,564, Then 42,000, Then 55,000

The clearest measure of how quickly the situation escalated is the evacuation count. As of 7:50pm on September 13, 31,564 people had been relocated from at-risk areas, according to Xinhua. By 8am on September 14, the provincial emergency management authorities put the figure above 42,000. By the evening of September 14, more than 55,000 people had been evacuated, according to the provincial emergency management bureau - a 74 per cent increase in roughly 24 hours, and a figure that officials did not present as final.

Wuzhishan raised its flood and typhoon control response from Level II to Level I - the highest tier in the system - at 7:30am on September 14, and ordered the suspension of classes, work, business operations, production and transportation, while closing tourist attractions. Thirteen cities and counties across the island, including Sanya, Qionghai, Baoting, Baisha and Chengmai, suspended school classes.

Wanning went further, halting classes, work, business operations, transportation and ferry services, and shutting its tourist sites. Qiongzhong introduced similar measures in stages. More than 55,000 people moving out of harm's way in a single province is a mass operation, and it reflects a doctrine that has hardened in China over the past decade: move people first, count the damage later.

Reservoirs Opened, Roads Cut, Water Off

With the ground saturated, the province turned to its reservoirs as a pressure valve. In Dongfang city, the Daguangba reservoir increased its discharge rate from 3,000 cubic metres per second to a range of 4,000 to 5,500 from 9am on September 14, and the Gezhen reservoir followed, rising from 3,200 cubic metres per second into the same band, according to CCTV. River levels in Qionghai surged as the releases moved downstream. Residents along the channels were told to stay away from the waterways, with swimming and fishing prohibited in and around the river channels.

The transport network absorbed the consequences. Sections of the S10 and S26 expressways, along with a tourist road looping Hainan Tropical Rainforest National Park, were closed after hazards were reported, the Hainan highway administration said. For Wuzhishan, a city of about 112,000 residents, the interruption was more basic: no piped water, no gas.

A Free Trade Port Tested Six Months Into Its New Customs Regime

The flooding lands on Hainan at a delicate moment. On December 18, 2025, China launched island-wide special customs operations across the province, converting an area of more than 30,000 square kilometres into the world's largest free trade port by area - a special customs supervision zone that sits inside China's territory but outside its ordinary customs regime.

The arrangement runs on what officials call "freer access at the first line, regulated access at the second line": goods arriving from overseas enter the island under a zero-tariff list that expanded from about 1,900 categories to more than 6,600, covering roughly 74 per cent of all goods categories, while standard customs controls apply to goods moving from Hainan to the mainland. A 15 per cent corporate income tax rate applies on the island, and imported goods processed in Hainan with at least 30 per cent value added may enter the mainland duty-free.

The numbers have followed. By the end of February 2026, Hainan's total goods imports and exports had reached 65.49 billion yuan, up 29.1 per cent year on year and ahead of the national average by 14 percentage points, with exports alone up 55.4 per cent. Since the customs launch, total foreign trade in goods has reached 173.98 billion yuan, and average clearance time for imports has fallen 20 per cent. More than 300 foreign-invested companies have registered since December 2025.

None of that infrastructure was exempt from the rain. Thirteen cities and counties closed schools, eight closed tourist attractions, expressways shut and reservoirs were opened - the ordinary machinery of a disaster response, applied to an island that is also China's most ambitious trade experiment. Provincial authorities have not yet published a damage estimate, and the effect on agricultural output in the island's tropical interior, where the Li and Miao autonomous counties took the heaviest rainfall, is not yet quantified.

Japan's Warning Gap, One Month After Chiba

For readers in Japan, the past five days in Hainan will sound familiar. On August 13 and 14, record rainfall struck Chiba Prefecture, causing widespread flooding and landslides across the Kanto region. The Japan Meteorological Agency designated the event the "August 2026 Chiba Heavy Rains" on August 14 - a naming convention the agency reserves for disasters of severe impact. Chiba Prefecture's official tally, issued at 4pm on August 19, reported 13 dead and one missing.

What makes Chiba relevant here is not the similarity of the damage but the behaviour of the warnings. The JMA issued its first-ever Level 5 emergency heavy rain warning for Chiba Prefecture at 7:30pm on August 13 - roughly an hour and a half after the first linear rainband had formed over the prefecture at 5:58pm. Two more rainbands followed, at 8:58pm and at 2:08am on August 14. No early forecast was issued before the first band appeared, even though the agency operates half-day advance forecasts and short-term alerts flagging potential formation within three hours - the latter introduced only in late May 2026 as a more precise replacement for the half-day model.

The JMA's own Weather Risk Management Division was candid about the limits. "There are still aspects of the formation mechanism of linear rainbands that remain unexplained," an official told the Asahi Shimbun, adding that while the agency expected heavy rain warranting advisories and warnings, "we could not foresee linear rainbands forming to this extent." Emergency heavy rain warnings are, by design, criteria-based and reactive, triggered once accumulated rainfall crosses thresholds. That is the same structural weakness visible in Hainan, where the record at Wuzhishan was measured after the fact and the mass evacuation followed the flood, not the forecast.

Japan has been reworking that layer of its system. The JMA announced a major overhaul of its weather alert framework, effective April 28, 2026, and the Chiba disaster became the first real test of the revised architecture. The lesson from both sides of the monsoon corridor is identical: forecasting has improved, but the gap between a rainband forming and a warning reaching a household has not closed.

What to Watch For

Three things will determine how this disaster is scored. First, whether the evacuation count has peaked - the provincial emergency management bureau's 55,000 figure came as more rain was still forecast, with 100 to 150 millimetres expected across eight cities and counties through the morning of September 15 and isolated totals above 250 millimetres. Second, the casualty and damage record: no deaths had been reported in Wuzhishan as of September 14, and no provincial figure has been published, which leaves the question of whether the pre-emptive evacuation worked unanswered.

Third, the recovery clock. Wuzhishan is running without piped water or gas, expressway sections remain shut, and the reservoirs that were opened to protect the island's cities will need to be refilled and re-regulated before the interior's farms, rubber plantations and tourist routes return to normal. For Hainan's free trade port, the test is not whether the rain stopped the customs regime - it did not - but whether the island can restore basic infrastructure quickly enough to keep the confidence its December opening was designed to create.

For Japan, the comparison is worth holding onto. Chiba showed that even a warning system that issues its highest alert can do so after the water has already arrived. Hainan's record at Wuzhishan, broken 68 years after the city began keeping records, is the other half of that same problem.

By Kenji Tanaka, Staff Writer

This article was produced with AI-assisted research and editorial support. Sources: CGTN, Xinhua, China Daily, Global Times, CCTV News, Hainan Provincial Meteorological Service, Hainan Provincial Emergency Management Bureau, Japan Meteorological Agency, Asahi Shimbun, Chiba Prefectural Government.