To assess the impact of underlying surface modification on low-visibility weather at the Foshan New Airport site, this study employed a combined approach of numerical modeling and observational data analysis. The evolution characteristics of visibility, low cloud cover, and relative humidity before and after surface modifi-cation were analyzed. Results indicate that: (1) Low clouds and low visibility events at the preselected site predominantly occurred from predawn to early morning with similar diurnal patterns, exhibiting annual frequencies of 11.0% and 19.7% respectively; (2) Simulations demonstrated that post-construction altera-tions in surface properties and terrain elevation induced localized warming and reduced relative humidi-ty—particularly at night where decreases exceeded 10%. This effectively inhibited fog formation and significantly improved visibility, with maximum improvements exceeding 10 km; (3) Concurrently, the markedly elevated high-humidity layer suppressed cloud condensation, reducing low cloud frequency. This work quantitatively reveals the suppressive effect of surface modification on low-visibility conditions, providing direct scientific support for flight safety threshold design and meteorological risk anticipation in airport operations, while establishing a climate impact assessment framework for siting comparable major infrastructure projects such as transportation hubs.