Abstract: Based on daily meteorological data from 14 county-level stations across Xinzhou City during 1990~2024, this study systematically investigates the spatiotemporal evolution characteristics of potential evapotranspiration (ET₀) and its dominant meteorological drivers using the Penman-Monteith (P-M) model, principal component analysis, sensitivity analysis and contribution rate analysis. The results show that the average annual ET₀ in Xinzhou City is 1029.1 mm, exhibiting a significant increasing trend over the past 35 years at a linear rate of 27.02 mm/10 a. Spatially, ET₀ displays a"high in the northwest, low in the southeast" pattern. Intra-annually, ET₀ follows a unimodal distribution, peaking in June (152.5 mm) and reaching its minimum in December (23.9 mm). Mann-Kendall test indicates a significant abrupt change in ET₀ in 2016, with post-change values increasing by 67 mm compared to the pre-change period. The contribution rates of dominant meteorological factors are ranked as wind speed (8.17%)>minimum temperature (5.67%)>relative humidity (4.05%)> maximum temperature (1.93%). Although ET₀ is most sensitive to relative humidity, it is not among the top contributors. Regionally, ET₀ in western counties is primarily controlled by maximum temperature, eastern areas are dominated by wind speed, and central regions are mainly influenced by humidity. The key mechanism underlying the"evaporation paradox" observed in Ningwu is the substantial decline in wind speed (-20.95%). This study represents the comprehensive elucidation of the multi-factor synergistic mechanisms governing ET₀ in Xinzhou City, highlighting the predominant role of wind speed and the region-specific nature of the evaporation paradox. These findings hold significant implications for drought-tolerant coarse grain cultivation, regional water resource management, and climate change adaptation strategies in Xinzhou.