The sea surface temperature (SST) is an important physical property that describes ocean characteristics. However, SST monitoring in harsh marine environments has a discontinuity problem in field observation using a research vessel. Therefore, correcting the missing data is essential in the preprocessing of the observation data because the missing data frequently occurs in the sea water temperature observation system. Especially, observation stations based on the collection and analysis of field samples repeatedly and periodically generate missing data during weekends and bad weather. In this study, a statistical method (Multiple Imputation, MI), a regression model (Auto-Regressive Integrated Moving Average, ARIMA), and an artificial neural network method (Long Short Term Memory, LSTM) were tested to find an optimized method for correcting the missing SST data among coastal stationary observation data. Most of the missing SST data at the Jumunjin observatory were from weekends. The models were implemented by correcting the SST for 2 days (weekends) based on SST data for 5 days (weekdays). Models were evaluated using Root Mean Square Error (RMSE) and Mean Absolute Error (MAE), and each model was compared using the residuals between predicted and measured values. Our study indicates that the LSTM model shows relatively better performance compared to MI and ARIMA.