Urban microclimate is very much influenced by the various anthropometric factors like pollution, population growth, scarce vegetation, lack of significant open spaces and so on. Built environment also in a very significant manner contributes in this influence. Considering the building environment of the city, factors like building layout, street geometry contribute a key role in altering the urban micro climate. The comfort of the interior spaces can be improvised with either of the active or passive techniques. Outdoor comfort is seldom thought of .Though there are many aspects of the built environment considered as factors in influencing outdoor thermal comfort, this paper focuses on the contribution of street geometry. To understand the influence of street geometry on outdoor thermal comfort traditional and the modern streets layout are documented and analyzed. The outcome of this paper is to establish the relationship between the elements of street geometry and the outdoor thermal comfort index PET.