Lake Chad, once Africa’s largest freshwater body, has been an important resource supporting livelihoods, agriculture, and biodiversity across the Lake Chad Basin. However, the lake has been generally shrinking drastically, but more in the North than the South of the Lake due to climate change and anthropogenic factors such as population growth and unsustainable water use. This study employs geospatial analysis to assess the impacts of physiography (topography and drainage), pedology and climate (precipitation, temperature, and relative humidity) on Lake Chad’s surface water dynamics. Using SRTM-GTOPO_U30 DEM data, the study classifies the relief of the Chad Basin into various elevation zones, highlighting the Bodere Depression as the most hydrologically active area. Drainage analysis reveals that while the southern part of the lake is replenished by River Chari and its tributaries, the northern section lacks significant inflows, contributing to its higher water loss. Soil analysis indicates that the northern lakebed consists of highly permeable soils, leading to poor water retention, whereas the southern region has low-permeability soils that facilitate water accumulation. Climatic data from WorldClim 2.1 and NASA-Power satellite data show significant spatial and temporal variations in precipitation and temperature across the basin. Rainfall analysis from 1981 to 2022 reveals a stark north-south gradient, with the southern part receiving significantly more rainfall (up to 1534 mm annually) than the arid northern region (as low as 4 mm). The coefficient of variation (CV) analysis indicates that rainfall is more erratic in the north (CV = 32.3%) compared to the south (CV = 25.46%), leading to inconsistent water availability. Furthermore, temperature trends indicate prolonged periods of extreme heat in the northern basin, which further worsens evaporation and water loss. The findings highlight the complex interplay of physiographic and climatic factors in Lake Chad’s hydrology. The urgent need for sustainable water management policies to mitigate water loss and enhance resilience in the Lake Chad Basin was recommended, while. Hydrological modeling of water balance dynamics in Lake Chad under future climate scenarios was suggested for further studies.