1937 Hong Kong typhoon

The 1937 Great Hong Kong Typhoon was one of the deadliest typhoons in Hong Kong history, with a death toll estimated between 11,000–13,000. Part of the 1937 Pacific typhoon season, the tropical cyclone originated on 24 August to the south of Guam, which proceeded generally to the west-northwest. On 1 September the storm entered the South China Sea, and early the next day, the typhoon passed just south of Hong Kong before making landfall in southern China. It weakened after moving ashore, dissipating on 3 September.

Ahead of the storm's landfall, the Hong Kong Observatory (HKO) issued warning signals and set off explosives, known as a typhoon bomb, to warn the public. During its closest approach, the typhoon produced the strongest ever wind gust in the territory, reaching 241 km/h (150 mph) before the anemometer stopped, until it was surpassed by Typhoon Wanda in 1962. Unofficial nearby observations recorded gusts as high as 268 km/h (167 mph). The typhoon also produced heavy rainfall and high tides, with a high water mark at Tai Po estimated at 6.25 m. The typhoon killed at least 11,000 people, possibly as many as 13,000, many of them fishermen, with 1,855 fishing boats wrecked, as well as 28 ships bound for the ocean. Across the territory, the storm damaged houses, factories, roads, and rail lines, with damage estimated at HK$1 million (US$300,000). Nearby Macau lost 21 people.

Background
Ahead of the typhoon, Victoria Harbour was described as "crowded" in newspapers, amid a naval blockade of eastern China amid the Second Sino-Japanese War. Time described the harbor as seventh busiest in the world... always alive with yachts, junks, ferries, sampans, freighters, liners, men-of-war. The Hong Kong Observatory (HKO) was established in 1883, and a year later, the agency warned the public of an approaching typhoon using a gun. The system was replaced with bomb detonations, beginning in 1907. A decade later, the HKO introduced a numbered warning system to the public, with no. 1 as standby. The highest rating, no. 10, meant the potential for typhoon conditions, or maximum sustained winds of at least 119 km/h (74 mph).

Meteorological history
The origins of the typhoon were from a storm located 320 km (200 mi) south of Guam on August 24. The September 1937 issue of the Monthly Weather Review described that "there was little evidence of its potentialities", as the storm moved west-northwestward across the western Pacific Ocean. On August 28, the USS Ramapo encountered the storm, observing an barometric pressure of 1003 mbar (29.61 inHg), and sustained winds of 61 km/h (38 mph). The observations suggested that the storm passed just south of the ship, although the intensity of the system was unknown at that point. Around August 30, the storm turned more to the northwest, causing it to remain north and east of majority of the Philippines. On September 1, it went through the Balintang Channel, passing 48 km (30 mi) south of Basco, Batanes. A station there recorded a pressure of 986 mbar (29.102 inHg), as well as a force 12 on the Beaufort scale, indicating hurricane-force winds. Thereafter, the typhoon entered the South China Sea, passing just north of Pratas Island, where a pressure of 993 mbar (29.327 inHg) was recorded.

As the typhoon moved across the northern portion of the South China Sea, it intensified rapidly as it moved toward the southern Chinese mainland. On September 2 around 21:00 UTC the typhoon made landfall just west of Hong Kong, after passing only 12 km (7 mi) south of the British colony. The lowest pressure recorded at the HKO was 958 mbar (28.298 inHg), while at the harbor, the SS Shuntien observed a pressure of 953 mbar (28.15 inHg). The typhoon's exact intensity was unknown, as its squalls of winds surpassed the capacity of the anemometer, which was greater than 125 mph. The observations suggested that the typhoon struck with winds equivalent to a Category 3 on the Saffir-Simpson scale, or sustained winds of at least 180 km/h (112 mph). The typhoon continued inland and weakened, dissipating northwest of Macau on September 3.

Preparations and impacts
Late on 31 August the HKO, then known as Royal Observatory Hong Kong, issued warning signal no. 1, or standby. On the next day, the warning signal was raised to no. 5, which meant that gale force winds were expected for the territory. The issuance prompted larger vessels to leave harbor and seek shelter in nearby bays. Fishermen and travelers left their ships for typhoon shelters. The HKO upgraded the warning further to no. 10, meaning that typhoon-force winds were expected, at 17:58 UTC on September 1 (1:58 a.m. September 2 local time). Twelve minutes later, officials fired typhoon bombs to warn the public. This marked the last occasion that typhoon bombs were used. The no. 10 warning signal was issued overnight, and less than two hours before the typhoon made its closest approach. As a result, the typhoon's ferocity was largely unexpected.

As it moved ashore southern China, the typhoon produced a variety of damaging effects. Wind gusts reached at least 241 km/h (150 mph) in Hong Kong, when the piston of the anemometer stopped and failed to record any higher measurements. This was the highest wind gust ever recorded by the HKO, until it was surpassed by Typhoon Wanda in 1962, which produced a gust of 259 km/h (161 mph). However, a private anemometer 2 mi east of the HKO recorded a wind gust of 268 km/h (167 mph) during the 1937 typhoon. The mean hourly wind average in the territory reached 109 km/h (68 mph). Along the coast, the powerful typhoon increased tides, with waves estimated at 30 ft in Tolo Harbour. The high water mark at Tai Po was estimated at 6.25 m, corresponding to a storm surge of 3.81 m. Victoria Harbour experienced a slightly smaller storm surge of 1.98 m. During its passage, the typhoon also dropped heavy rainfall, totaling 5.055 in.

The powerful typhoon killed thousands of people in Hong Kong, with a death toll between 11,000–13,000. This accounted for roughly 1% of the territory's population of 1 million. However, many of the bodies were washed away and never found, with roughly 500 corpses found in the days after the typhoon. Fishermen accounted for majority of the deceased, after the typhoon capsised 1,855 fishing boats. These included sampans, or houseboats, as well as 28 ships bound for the ocean. Other sailors were unaware of the approaching storm. High tides washed many boats ashore and broke other vessels from their moorings, including the Asama Maru, the Conte Verde, and the Van Heutsz. The steamer An Lee broke from its moorings and struck HMS Suffolk, causing 12 people to jump ship, one of whom missed and drowned. The An Lee later hit HMS Duchess. Twenty ships sent out SOS distress signals.

In mainland Hong Kong, the typhoon swept away an entire village in Tai Po Market, resulting in an estimated 300 fatalities. About half of Sha Tau Kok was wrecked, with 30 people killed there. Across Hong Kong, the storm damaged houses and factories while also resulting in power and telephone outages. The winds uprooted trees and knocked down branches. During the height of the storm, nine buildings caught fire and were destroyed, resulting in dozens of deaths, after the fire brigade faced difficulty reaching the area. The high winds tore through roofs, signs, and lampposts, littering the road with debris. The high tides washed away nearly a mile of the Kowloon–Canton Railway. British officials estimated the total damage around HK$1 million (US$300,000).

Outside of Hong Kong, newspapers described the effects in nearby Macau as having "suffered severely", with 21 fatalities in the territory. In nearby Canton, there was a "less severe buffeting" according to newspapers.

Aftermath
Police and other officials used rope to attempt rescuing people caught by the floods. At the harbour, tugs were required to assist beached or stranded vessels, although it took six months for the Asama Maru to be moved. The storm occurred concurrently with a cholera outbreak in Hong Kong amid the stagnant floodwaters. To prevent a larger outbreak, officials set up 50 clinics for vaccinations. Emergency resources were strained due to the ongoing war and naval blockade, although British and American air shipments helped with the supply. Flooded or blocked roads and railroads disrupted transport, with people in Hong Kong stranded for several days. Damage at Kai Tak Airport delayed international flights.

In 1938 the HKO published a report assessing the costs of typhoon damage over the preceding ten years. The 1937 typhoon accounted for 38% of the costs over the ten-year period, with the repairs reaching about HK$586,000.