2023 Pacific typhoon season

Few storms, many strong ones

Forecasters expected a busy year. With a moderate to strong El Niño developing, Tropical Storm Risk predicted in May about 29 tropical storms, 19 typhoons and an accumulated cyclone energy near 394, well above its 1965 to 2022 average of 25.7 tropical storms, 16.1 typhoons and an energy total of 290. It kept that outlook through the summer and even raised its typhoon count in August.

The season fell far short of those numbers. By the Japan Meteorological Agency's count it was the third least active on record for named storms, ahead of only 1998 and 2010, and the fourth year in a row with below-average activity. El Niño usually favours storm formation in this basin, but a long negative phase of the Pacific decadal oscillation suppressed development. The storms that did form were often long-lived and strong, so the archive's accumulated cyclone energy of 265.3 came much closer to normal than the storm count did.

Activity also avoided much of Southeast Asia. Only 11 tropical cyclones formed in or entered the Philippine Area of Responsibility, which tied 1998 and 2010 as the quietest year on record for the Philippines, and no tropical storm made landfall on mainland Vietnam, only the third such year since the country's independence.

How the season unfolded

The archive's first tropical observation came on 11 April from a weak depression that PAGASA named Amang and that came ashore in the Bicol region of the Philippines. Tropical Storm Sanvu formed near Pohnpei later that month and faded over open water. The first major system followed in May, when Mawar developed south of Guam on 19 May, became the season's first typhoon on 21 May and went on to its peak five days later. Typhoon Guchol followed in June but was held in check by the cool water Mawar had left behind in the Philippine Sea.

After a quiet end to June and early July, the season's main burst ran from mid-July to early October. Typhoon Talim crossed the South China Sea in mid-July, and Typhoon Doksuri and Typhoon Khanun formed within a week of each other late in the month. August brought Typhoon Lan toward Japan, while Saola, Damrey, Haikui and Kirogi all formed in the last ten days of the month, with Saola looping slowly off Luzon as Haikui headed for Taiwan. Tropical Storm Yun-Yeung reached central Japan in early September.

Typhoon Koinu formed at the end of September and struck southern Taiwan in early October, and Typhoon Bolaven exploded into a Category 5 typhoon east of the Mariana Islands a few days later. After Tropical Storm Sanba reached Hainan in mid-October, the basin went quiet for weeks. A depression in November never organised, and the last system, Jelawat, came ashore on Mindanao on 18 December. The archive records it at 30 knots on one-minute winds, below tropical storm strength, although the Japan Meteorological Agency named it.

Three Category 5 typhoons

Typhoon Mawar was the season's strongest cyclone. After brushing the northern tip of Guam as a Category 4 typhoon on 24 May, it completed an eyewall replacement and peaked on 26 May with one-minute winds of 165 knots and a central pressure of 891 hPa, making it one of the strongest Northern Hemisphere tropical cyclones on record in May. It then weakened over cooler water and in stronger wind shear as it passed east of Luzon and near Okinawa, and became extratropical south of Honshu on 3 June.

Typhoon Bolaven matched Mawar's peak wind. Shortly after passing south of Saipan, it strengthened from a Category 1 to a Category 5 typhoon in about 12 hours, and it reached 165 knots with a pressure of 897 hPa late on 11 October before recurving northeast over open water. Typhoon Saola was the third Category 5. It peaked at 140 knots and 917 hPa on 29 August near the Babuyan Islands, a strength the Joint Typhoon Warning Center confirmed only in a 2024 reanalysis after rating it Category 4 in real time.

The other major typhoons were Doksuri at 130 knots, Khanun at 125 knots, Lan and Koinu at 120 knots and Haikui at 105 knots. Khanun's winds rose by about 70 knots in a single day as it passed through the Philippine Sea in late July. Guchol peaked just below major strength at 95 knots.

Doksuri and the costliest typhoon on record

Typhoon Doksuri formed east of the Philippines in late July and intensified rapidly over the Philippine Sea, peaking at 130 knots on 25 July. It crossed the Babuyan Islands off northern Luzon as a strong typhoon and weakened through an eyewall replacement, then reorganised with a pinhole eye over the sea before striking Jinjiang in Fujian, China, on 28 July.

Wikipedia reports 137 deaths, 46 missing and 285 injured across the Philippines, Taiwan and China, including 27 people who died when the MB Aya Express capsized in the Philippines. Its damage estimate of about US$28.6 billion in 2023 dollars makes Doksuri the costliest typhoon on record and the costliest to strike mainland China, and it accounts for most of the losses that ranked 2023 as the second costliest Pacific typhoon season. Doksuri and Khanun together also strengthened the southwest monsoon over the Philippines and caused widespread flooding there.

Other landfalls and impacts

Mawar gave Guam its strongest storm since Typhoon Pongsona in 2002, with power cuts, a gust of about 105 miles per hour at the international airport and heavy rain. Wikipedia lists 6 deaths and about US$4.3 billion in damage in 2023 dollars across its path. Five months later Bolaven brought damaging winds and power cuts to Saipan, Tinian and Rota and minor damage to Guam.

Saola passed south of Hong Kong and Macau on 1 September as a strong Category 4 typhoon, prompting the Hong Kong Observatory's Hurricane Signal No. 10 for the first time since Typhoon Mangkhut in 2018, and then struck Guangdong. Wikipedia lists 3 deaths and about US$673 million in damage in 2023 dollars. Days later Haikui made landfall in Taitung County as the first typhoon of that strength to hit Taiwan since Typhoon Megi in 2016, then crossed to Fujian. Its remnants brought Hong Kong 158 millimetres of rain in one hour on 7 September, the highest hourly total since records began in 1884, and four people died in the flash floods there. Wikipedia lists 16 deaths from Haikui in total.

Farther north, Khanun battered the Ryukyu Islands with heavy rain and strong winds before making landfall on Geoje Island in South Korea on 10 August and crossing the whole Korean Peninsula, the first typhoon on record to do so from south to north since 1951. It left 13 dead and 16 missing. Lan struck Cape Shionomisaki in Japan on 14 August, displacing more than 237,000 people and cutting power to over 100,000 homes, with 1 death and about US$500 million in losses in 2023 dollars.

Koinu struck Hengchun in southern Taiwan in early October and later brought Storm Signal No. 9 to Hong Kong. Farther south, Talim struck Zhanjiang in Guangdong on 17 July after enhancing monsoon rains in Luzon, with 3 deaths. Sanba's precursor flooded central Vietnam, and in China the storm caused 4 deaths and about 5.82 billion yuan (US$796 million in 2023 dollars) in damage.

How the counts compare

This page counts 15 tropical storms and 11 typhoons from US-agency one-minute winds in the track archive. The Japan Meteorological Agency, which measures ten-minute winds, counted 17 tropical storms and 10 typhoons, and the Joint Typhoon Warning Center counted 17 tropical storms and 12 typhoons from its own warnings. Both agency totals include Dora, which crossed the date line from the central Pacific as a typhoon in August and kept its eastern Pacific name, but it is not among this page's storms. The Japan Meteorological Agency also named Jelawat, which the archive records below tropical storm strength on one-minute winds.

The two wind measures also classify individual storms differently. Talim was a severe tropical storm on the Japanese scale but a typhoon on one-minute winds, and Kirogi, which the Japan Meteorological Agency lowered to tropical storm strength in its post-analysis, also reaches typhoon strength in the archive. Damrey was rated a Category 1 typhoon by the Joint Typhoon Warning Center in real time, but the agency's 2024 post-analysis lowered it to a tropical storm, as the archive has it.

Three names were retired for the deaths and damage their storms caused. In February 2024 the Typhoon Committee removed Doksuri, Saola and Haikui from the rotation, replacing them with Bori, Saobien and Tianma, and PAGASA retired its local names Egay and Goring after each storm caused more than 1 billion pesos of damage in the Philippines. The season was also the first use of the names Yun-Yeung and Koinu, which had replaced Kai-tak and Tembin.