The largest earthquake in South Korea ( 5.8) since modern seismograph network began monitoring in 1978 occurred in Gyeongju on 12 September 2016. Because of the generally low level of seismic activity in the country, Korean citizens had not expected or thought about how to respond to such a large earthquake and its related aftershocks. After the event, Koreans were left feeling a certain level of apprehension. Responding to this situation, a temporary microelectromechanical system (MEMS)‐based seismic network was operated at six high‐school sites to monitor seismic activity in Gyeongju from 18 October to 18 November 2016. The purpose of this temporary real‐time warning system was not only to monitor aftershocks but also to provide an onsite earthquake drill in the event of an earthquake on the day of the College Scholastic Ability Test (which is held in November each year). The national college entrance examination is extremely important in Korea, and the government aims to avoid any interruptions to the exam. An earthquake drill manual was established for the first time for an effective response to possible earthquakes occurring on the day of the exam (17 November) in 2016. The MEMS network detected several aftershocks during the operating period but none on the day of the exam. The real‐time MEMS warning system represents a new type of earthquake‐monitoring system for South Korea.