This study aims to assess the seasonal impact of land use on daytime normalized urban heat island (DNUHI) and nighttime normalized UHI (NNUHI) in Ahvaz, one of the hottest cities in Iran. To this end, 63 corrected Landsat images acquired in 2024 were used, and daytime land surface temperature (DLST) and nighttime land surface temperature (NLST) were derived for the four seasons. Thereafter, DNUHI, NNUHI, and normalized UHI (NUHI) indices were derived by normalizing the temperature differences between urban and non-urban areas. A land use layer consisting of 14 classes was overlaid with the thermal data to investigate the role of land use type in controlling thermal patterns. The results showed that the highest DNUHI values were observed in industrial (0.14–0.20) and oil (0.12–0.19) areas, which generated the highest daytime heating. At night, the highest NNUHI values were recorded in industrial (0.12–0.24), military (0.07–0.20), and oil (0.08–0.18) land uses, indicating the strong heat storage capacity of these areas. In contrast, green spaces, orchards, and agricultural lands showed the lowest DNUHI and NNUHI values (about 0.01–0.06). These findings can inform the design of sustainable climate strategies, the development of green spaces, and land use management to reduce urban heating.