The impact of weather conditions on the yield of yellow lupin Juno cultivar was performed for the years 1986-2008. The source material came from five experimental and meteorological stations located in northern Poland. The research used multiple regression method with stepwise choice of variables and the created equations were evaluated using the coefficient of determination R², adjusted coefficient of determination R²adj, Cross Validation procedure (R²_pred) and F-Snedecor test. In the studied stations observed considerable variation of weather factors in different years, which had a significant impact on the date of beginning and length of periods of yellow lupin development and the amount of yield. Based on created weather – yield of lupin models verified by CV test, it was found that the yield of Juno cultivar depended mainly on the maximum temperature of flowering and the minimum temperature in the initial stages of plant growth.