The accuracy of descriptive statistics might be influenced by the existence of outliers in data sets. An observation which might not be considered as an outlier in the univariate case might be a multivariate outlier. Therefore, determination of outliers might make multivariate analysis more robust by providing an opportunity for making required corrections before modelling studies. This paper presents the implementation of the two-dimensional correlation method in the determination of multivariate outliers among the observations of six precipitation stations in Turkey. The two-dimensional correlation method considers the averages of the parts of the whole series instead of the average of the whole series and enables determination of the location of the outlier in the compared series. The obtained results point out that an outlier analysis for hydrologic variables should consider the two-directional behavior and the presented two-dimensional correlation method proves to be a strong alternative to be used in outlier and irregularity detection studies even with a limited number of available data. The 2DCorr software used in the study is freely provided as a supplementary material.