To assess the relative roles of climate, salt type and water supply in the salinization of irrigated soils in Southern Fergana (Fergana Region, Uzbekistan). Annual air temperature and precipitation series of the Fergana weather station for 2000–2025 were analysed; the records for 2021–2024, which duplicate earlier years, were excluded from the main analysis. The de Martonne aridity index was calculated. At nine key plots (85 soil profiles, September 2025), dry residue, Cl⁻ and SO₄²⁻ were determined in water extracts of the 0–100 cm layer. Data on soil salinity, groundwater depth and mineralization for 17 districts (369,157 ha, 1 October 2025) and on groundwater depth for 1 October 2025 and 1 October 2026 were also analysed. Linear regression, Pearson correlation and Welch’s t-test were applied. In the series without duplicated years, annual precipitation decreased by 4.03 mm/yr (p = 0.017) and the aridity index fell by 0.166 units/yr (p = 0.017); warming was not significant over 2000–2025 (+0.019 °C/yr; p = 0.251) and was found only for 2010–2025 (+0.097 °C/yr; p = 0.033; n = 12). Dry residue is almost entirely controlled by sulfate (r = 0.997), not chloride (r = 0.581; p = 0.101); SO_₄/Cl exceeds 5 at all plots (6.5–33.7). Salt stocks in long-irrigated soils (67.7 ± 32.5 t/ha) are about half those of newly reclaimed soils (146.6 ± 22.2 t/ha; p = 0.013), but the plots differ in geomorphological position. The share of saline land in districts correlates with the share of mineralized (r = 0.63) and shallow (r = 0.72) groundwater. Irrigation water supply declined by 23.3%. Between 1 October 2025 and 1 October 2026 the share of land with groundwater at 1–2 m decreased from 39.1% to 26.5% and that at 2–3 m increased from 31.3% to 43.1%, whereas the share deeper than 5 m (23%) did not change; the groundwater measurement method changed in 2026, so the shift is treated as indicative. Soil salinity in Southern Fergana is of the sulfate type; the data support a predominantly geogenic (residual) origin, which is not fully proven because cations and gypsum were not determined. Salinity is concentrated in low-lying areas with groundwater close to the surface. Lower salt stocks in long-irrigated soils may reflect irrigation with functioning drainage but also differences in landscape position. Short-term salinity risk may be governed mainly by water management, whereas climate sets the long-term background; this was not tested quantitatively.