Rural mountain springs remain vital sources of drinking water for isolated Mediterranean communities, yet their vulnerability to climatic variability and anthropogenic pressures remains poorly documented in many North African massifs. This study presents an integrated hydrochemical, microbiological, and multivariate statistical assessment of eleven perennial springs in the Séraidi area, Edough Massif, north-eastern Algeria. Twenty-two samples were collected during wet-season (March) and dry-season (July) campaigns in 2026. Eleven physicochemical parameters and thermotolerant (faecal) coliforms were analysed, and a weighted-arithmetic Water Quality Index (WQI) was calculated. Mean WQI values were 44.7 in March and 54.9 in July, with no statistically significant seasonal difference (paired Wilcoxon test, p = 0.147). Because pH and potassium accounted for 72.5% of the total index weight, WQI variation primarily reflected these parameters, particularly the higher potassium concentrations in July. Pearson correlation, principal component analysis (PCA), hierarchical cluster analysis (HCA), and Piper, Durov, and Gibbs diagrams were used to explore hydrochemical patterns and potential controlling mechanisms. PCA retained two components explaining 62.2% of the variance: a mineralization gradient associated with sulfate, electrical conductivity, potassium, and nitrate, and a temperature–hardness contrast involving temperature versus calcium, magnesium, chloride, and bicarbonate. HCA primarily separated samples by campaign. These patterns are descriptive and require cautious interpretation because the dataset comprises only eleven springs sampled twice. Hydrochemical diagrams indicated mixed Ca–Mg–HCO₃/Cl–SO₄ facies, suggesting that water–rock interaction is the main hydrochemical control, with a possible atmospheric contribution to sodium and chloride. Thermotolerant coliforms were not detected in March but occurred in five springs in July, at 40–100 MPN/100 mL, exceeding the World Health Organization’s recommended criterion of absence in 100 mL. Microbiological contamination was not significantly associated with WQI or the first principal component. The causes of seasonal increases in potassium, nitrate, and sulfate, and the origin of faecal contamination, could not be established from the available data. These findings demonstrate that physicochemical indices alone cannot establish the sanitary safety of spring water. Repeated monitoring integrating hydrochemical and microbiological analyses is therefore recommended to support the protection and sustainable use of rural mountain springs in Mediterranean environments.