Rainfall seasonality in Serbia is examined trough the analysis of several indices: seasonality index (SI), individual seasonality index ( \({SI}_{i})\) , and replicability index (RI). Based on data from 14 synoptic stations that are well distributed over Serbian territory, spatial distribution of general seasonality index \(\overline{SI}\) , mean individual seasonality index \(\overline{{SI }_{ind}}\) , and \(RI\) are analyzed in two subperiods (1961–1990 and 1991–2020). The modified Mann–Kendall test (MMK) and Sen’s slope methods are used to investigate the possible trends and its magnitudes in time series of \({SI}_{i}\) . The values of \(\overline{SI}\) show that precipitation regime in Serbia is very equitable or equitable with definite wetter season. For the entire Serbian territory, the values of RI are low, indicating that the month of maximum rainfall occurs over large spread of months along the studied periods. The existence of significant negative correlation between RI and longitude is found. Results show a highest influence of the North Atlantic Oscillation and East Atlantic/West Russia pattern on rainfall seasonality in Serbia.
