Tropical Storm Sinlaku was a weak tropical cyclone that impacted Vietnam, Thailand and Laos in August 2020. Beginning as a tropical depression on July 31 in the South China Sea, Sinlaku was the fifth storm of the 2020 Pacific typhoon season. It gradually organized as it took a slow west-northwest course, strengthening into a tropical storm the following day despite its monsoonal structure. The storm subsequently made landfall in Vietnam as a broad but weak tropical storm. Persistent land interaction weakened Sinlaku, leading to its dissipation on August 3.

2020 was regarded as the most active tropical cyclone year on record, documenting 104 named tropical systems. During the year, 141 tropical cyclones formed in bodies of water known as tropical cyclone basins. Of these, a record-high of 104, including three subtropical cyclones in the South Atlantic Ocean and three tropical-like cyclones in the Mediterranean, were named by various weather agencies when they attained maximum sustained winds of 35 knots. The strongest storm of the year was Typhoon Goni, peaking with a pressure of 905 hPa (26.72 inHg). The deadliest storm of the year was Hurricane Eta which caused 175 fatalities and another 100+ to be missing in Central America and the US, while the costliest storm of the year was Hurricane Laura, with a damage cost around $19.1 billion in the Greater Antilles, The Bahamas, and the Gulf Coast of the United States.