Russell’s viper (Daboia russelii), with a near-country-wide distribution across the Indian subcontinent, causes the highest number of snakebite deaths and disabilities. A considerable geographic venom variation documented in D. russelii, among others, makes it the clinically most relevant snake species. However, biotic and abiotic factors that drive this variation remain uninvestigated. Hence, we assessed the influence of bioclimatic factors on the functional venom variation through statistical modelling. D. russelii venoms (n=115) were sourced from varied biogeographies across >6600 km, followed by the functional characterisation of major toxins. Multiple regression models generated revealed the impact of historical climatic conditions on venom variability. Phenotype maps that predict venom biochemistries of D. russelii across its range distribution were generated, providing valuable insights for deploying targeted therapies. Overall, our findings provide novel insights into the effects of abiotic factors on snake venom variation and its implications for enhancing the effectiveness of snakebite therapeutics.