**4. Conclusions**

Rainfall variability is crucial for rational water resource management especially in Mediterranean countries, such as Greece, with rainfalls presenting temporal and spatial variation. In this study, monthly rainfall data from nine meteorological stations in the central Pindus mountain range were collected and analyzed for the period of 1961–2016. The conclusions reached are summarized below:


and summer rainfalls and the early 1970s for the winter rainfall in most of the stations. Finally, the average trend magnitude per decade, using Sen's slope method, was −1.9% for the annual rainfall, −3.2% for the winter rainfall, +0.7% for the autumn rainfall, +0.2% for the spring rainfall, and +2.4 for the summer rainfall. The observed downward trends in rainfall in Greece was linked mainly to a rising trend in the hemispheric circulation modes of the North Atlantic Oscillation Index and its connection with the Mediterranean Oscillation Index [47]. In addition, the link between precipitation variability in Greece and the Mediterranean pressure oscillation is very reasonable from a physical point of view.


**Author Contributions:** S.S. analyzed the GIS data, investigated the spatial distribution of rainfall, and wrote the paper, whereas D.S. collected the meteorological data and applied the Mann–Kendall statistical test.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
