Temperature distribution and cooling rate during welding have a significant effect on the mechanical and the metallurgical properties of a weldment. The type of microstructure, grain growth, hardness and residual stress in a weldment are very much influenced by the temperature distribution and the cooling rate. In the present work a three-dimensional transient finite element analysis of heat transfer in are welding has been considered by taking into account the Gaussian distribution of welding arc, temperature dependent material properties and enthalpy. Effect of arc length was also investigated. Theoretically estimated values of temperature distribution and cooling rate were compared with those published in literature. The results show a close agreement between the predicted and the published values.