This study examines the spatial and temporal variability of precipitation seasonality across Serbia using various seasonality indices. The research focuses on understanding the intra- and inter-annual variability of precipitation regimes over two sub-periods: 1946–1984 and 1985–2023. For this purpose, monthly precipitation data from 24 synoptic stations across Serbia were analyzed using seasonality indices such as the General Seasonality Index ( \(\overline{SI}\) ), Individual Seasonality Index (SIi), Mean Individual Seasonality Index ( \(\overline{{SI_{i} }}\) ), and Replicability Index (RI)). The results shown on the SI maps indicate a more irregular rainfall distribution during the first sub-period, with a noticeably higher seasonality in the northern part of Serbia. The mean SIi shows an increasing gradient from southwest to northeast, with the highest variability shifting from the central and southeastern parts (1946–1984) to the northern and eastern parts of Serbia (1985–2023). Minimum values reveal a shift from a “very equitable” regime in the first sub-period to “equitable with a definite wetter season” in the second, while maximum values generally decreased. RI values remain low across Serbia, reflecting significant variability in precipitation regimes.
