Dynamics o f Daytime Seasonal Variability of Land Surface Temperature and Its Driving Factors: A Case of Dire Dawa City.

Abstract

Rapid urbanization in Dire Dawa City, Ethiopia, has led to significant increases in LST, affecting both socioeconomic and environmental conditions. This study investigates the dynamics of seasonal and temporal variations in daytime LST from 2002 to 2024, addressing LST fluctuations during wet and dry seasons. By analyzing the influence of LULC changes; this research identifies key factors driving LST variability. Employing a mixed-methods approach, the study assesses seasonal patterns and temporal trends in LST, correlating them with, land cover changes, and Land cover indices. LST data derived from thermal bands using an emissivity-corrected Landsat imagery by using Single-Channel Method for Landsat 7 and Split-Window Method for Landsat 8 images. Analyses using the NDVI and the NDBI quantified the extent of vegetation and built-up areas. In contrast, rural areas stayed cooler this season due to higher soil moisture in both bare and vegetated lands, which enhanced evapotranspiration and provided a natural cooling effect. Overall, throughout these years, Kiremt consistently represented the coolest temperatures, whereas Tseday typically recorded the warmest conditions, highlighting a trend of increasing temperatures across all seasons in Dire Dawa City for all LULC. The mean LST experienced fluctuations, beginning at 24.1°C in 2002, increasing to 25.75°C in 2012, and then rising again to 27.25°C in 2017. By 2024, the average LST reached 29.7°C, reflecting an overall warming trend during the Study. These changes demonstrate how sensitive LST is to seasonal variations and urbanization. These results illustrate the complex relationship between different land cover types and LST, which fluctuates with the seasons based on how land cover responds to climatic conditions. The study underscores the urgent need for integrated urban planning and sustainable development that balances growth with environmental preservation, especially in managing urban thermal environments. These insights are vital for planners, stakeholders, and policymakers in crafting strategies to address the negative impacts of rising Land Surface temperatures.