Growth rates, enzymatic activity, energy production, and nutrient processing are all directly impacted by temperature, which is a critical factor in determining microbial metabolism. From quick alterations in metabolic pathways to long-term adjustments in protein structures and membrane dynamics, microbes demonstrate a variety of adaptation mechanisms to temperature fluctuations. This chapter looks at how temperature affects important metabolic functions, including nitrogen cycling, glycolysis, and the tricarboxylic acid cycle, with an emphasis on thermophiles, mesophiles, and psychrophiles. The function of regulatory networks and stress response systems in microbial adaptations to temperature changes is also highlighted. Additionally, given the effects of global climate change on biogeochemical cycles, the chapter examines the wider ecological ramifications of temperature-induced changes in microbial activity. This chapter emphasizes the crucial role that temperature plays in determining the dynamics of ecosystems and microbial functions by connecting basic microbial physiology with application areas like industrial fermentation and bioremediation.