The spatial variability of precipitation in Slovenia was evaluated using correlation decay distance analysis (CDD). CDD analysis essentially explores how the correlation between neighbouring stations varies according to distance. We analysed CDD for the period December 2009–November 2019 using only those meteorological stations (n = 160) with no missing values and operating at same location for the whole analysed period. For each meteorological station, we calculated the threshold distance at which the correlation between series is higher than 0.707 (r2 = 0.5). The results indicate that the highest spatial variability in precipitation is during summer (CDD = 50 km), followed by spring (CDD = 76 km), autumn (CDD = 120 km) and winter (CDD = 141 km), when the spatial variability is the lowest. The spatial variability of precipitation is similar in spring and autumn (with the lowest variability of precipitation in E and SE Slovenia), and it is lowest in S Slovenia in summer and in NW Slovenia in winter. The variogram map indicates anisotropy in the correlation decay distance for spring precipitation. Higher values of semivariance are evident in the NE-SW direction, while semivariance values in the SE-NW direction are much lower.
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