In the quest to provide water security, solar energy-based water desalination systems have emerged as a promising solution to support the need for water supply. A solar still principally works on solar energy-based water distillation. Worldwide, numerous investigations have been carried out on solar stills to improve their efficiency and productivity. In the present work, an ANSYS Fluent module has been used to investigate numerically the variation of temperature and radiation absorption coefficients on the solar still performance under different water depths. It has been observed that with the increase in water level, the maximum temperature achieved within the still decreases. The radiation absorption coefficient with a higher water level (0.0937 m) is 0.53967 m<sup>-1</sup> as compared to other cases with lower water levels (0.0625, 0.0312, and 0.0156 m), which have radiation absorption coefficients of 0.53999, 0.53999, and 0.53999 m<sup>-1</sup>, respectively. The experimentation with a hybrid setup of single slope solar still and a flat plate collector (FPC) [MANIT, Bhopal, India (23.2599° N, 77.4126° E)] has been used to record for three consecutive days during sunshine hours in January. The parameters have been analyzed for a comparative study of convective, evaporative, and radiative heat transfer coefficients.