We present time series of temperature and salinity of the Aegean Sea using the data sets for the period from 1991 to 1996 from 15 oceanographic cruises to depict the temporal variability of the water masses of the Aegean Sea. This period covers an interesting large-scale change in the thermohaline circulation in the Eastern Mediterranean and the Aegean Sea. This change is known as the Eastern Mediterranean transient (EMT) and was first described during early 1990s. Our analysis reveals that very dense water formation in the Central Aegean Sea is partially due to the anomalous decrease in winter atmospheric temperature although this alone cannot completely account for the formation of the dense water. A synchronous increase in surface salinity accompanied by low temperature values in the winter months is also necessary for the EMT event to occur.