A curvilinear regression study of weather factors with the wheat yield et Dharwar is made by the successive approximation technique developed by Ezekiel and Fox (1950). Various weather factors are tried and the following tentative conclusions are drawn. An optimum of about 160C minimum temperature 29.30C maximum temperature and 220 to 230C mean temperature with 60 to 65 hours of bright sunshine per week and 50 to 60 percent humidity appear to be the most favourable condition for wheat in Dharwar. An optimum total water requirement may be assessed as equivalent of 40 to 50 cm of rainfall during the period July to end of the Vegetative phase.