The temperatures on the outside of an oven will largely depend on the material used to build the oven, they type of cladding done, and the length of use. For home based oven that have mortar or mud cladding, they will rarely be hot on the outside. Because of the materials used in building and cladding an oven, heat from the fire in the oven is poorly conducted to the outside. Depending on how long the oven is used, then the heat change on the outside might be insignificant or might get warm.
Find more information on oven heating and transmission of heat to the outer layers in an oven on How to build a pizza oven#Thermal_Insulation.