Typhoon In-fa, known in the Philippines as Typhoon Fabian, was a very large and costly tropical cyclone that brought record amounts of rainfall to China in July 2021, becoming the second-wettest tropical cyclone ever recorded in the country. It was also the first storm to impact the city of Shanghai since Typhoon Mitag of 2019. The ninth depression, sixth tropical storm and third typhoon of the 2021 Pacific typhoon season, the system was first noted by the Joint Typhoon Warning Center as an area of low pressure, located east of the Philippines on July 14. Favorable conditions helped the storm to intensify, becoming a tropical depression, two days later and a tropical storm on July 17, being assigned the name In-fa by the Japan Meteorological Agency. Located in a weak steering environment, the system struggled to organize under dry air and moderate wind shear before organizing further. It continued to move mostly westward, strengthening into a typhoon and deepening quickly. The storm struggled to organize itself significantly due to continuous dry air intrusions and its frequent motion changes. On July 21, it reached its peak intensity according to the JTWC with winds of 175 km/h (110 mph); the JMA estimated a lower numbers of 150 km/h (90 mph) on the system. Nevertheless, the system reached its minimum barometric pressure of 950 hPa (28.05 inHg), three days later after passing through the Ryukyu's. As the system entered the East China Sea, marginal conditions started to take toll on the system, with In-fa weakening steadily and slowly, until it made its consecutive landfalls over Putuo District of Zhoushan and Pinghu on July 25 and 26, respectively, as a tropical storm. For the next couple of days, the storm slowly moved inland while gradually weakening, before turning northward on July 29. Later that day, In-fa weakened into a remnant low over northern China. The remnants continued their northward trek for another couple of days, before dissipating near North Korea on July 31.

The 2021 Pacific typhoon season was the second consecutive to have below average tropical cyclone activity, with twenty-two named storms, and was the least active since 2011. Nine became typhoons, and five of those intensified into super typhoons. This low activity was caused by a strong La Niña that had persisted from the previous year. The season's first named storm, Dujuan, developed on February 16, while the last named storm, Rai, dissipated on December 21. The season's first typhoon, Surigae, reached typhoon status on April 16. It became the first super typhoon of the year on the next day, also becoming the strongest tropical cyclone in 2021. Surigae was also the most powerful tropical cyclone on record in the Northern Hemisphere for the month of April. Typhoons In-fa and Rai are responsible for more than half of the total damage this season, adding up to a combined total of $2.02 billion.