ABSTRACT Reinforced concrete and steel structural elements undergo premature degradation and lose strength primarily due to corrosion. Corrosion is an electrochemical phenomenon and its severity depends on number of environmental factors. Experimental data on corrosion of steel is important for making engineering decisions towards improving the service life of civil infrastructures. No recent dataset on atmospheric steel corrosion under Indian coastal environment is found to be available in the literature, and hence this research attempts to address some of the literature gap. This paper presents experimental study conducted to determine the corrosion rate of TMT, high-chromium steel (CRS) and stainless steel rebars exposed in actual coastal and inland regions for a period of one year. The site locations were located in southeastern parts of Tamilnadu state in India. Based on the first-year corrosion rate, the corrosion rate after extended exposure (10-years) was determined based on ISO 9224 recommendations. Atmospheric steel corrosion map of Tamilnadu state was developed using inverse distance interpolation technique. Microstructural studies indicated the formation of lepidocrocite (γ-FeOOH) phase composition in the rust products collected from coastal region.