Submited abstract includes the results of statistical calculations of the correlations existing between the climatological conditions and the yield, the quality and the growth rate of three yellow lupine cultivars, including: Amulet, Juno and Radames. The experimental material originated from a series of experiments completed in the years 1996 – 2000 in 17 research stations throughout Poland. Temperatures and precipitations, being the main factors determining vegetation, yield and yellow lupine seed quality, varied in different years of the experiment and ranged from 8 to 75.4%. This, among others, had an effect on the seed yield which varied up to 34% and the protein content in seeds which changed up to 4%. Regression analysis involving testing many defining variables and the evaluation of the resulting models allowed for selection of a model that would be the most realistic. This was a negative correlation between the yellow lupine yield and the precipitation totals of August and April and a positive correlation of the yield and the temperatures of the end of March and the beginning of April. This equation’s adjustment co-efficient (determination - R2) was 87%. The April temperatures had a positive influence on the protein content, whereas the May and June temperatures had a negative effect on this quality. At higher precipitations (at the beginning of vegetation) the protein content in seeds increased, whereas in May it was reduced. Precipitation from June to August had a similar effect to the one at the beginning of the growth. The determination co-efficient of the regression equation incorporating the above correlations was 92%. The completed calculations produced a very precise mathematical model of the correlations between the vegetation period length and the weather conditions (even an adjusted R2 was higher than 0.9). Generally, it proves that the yellow lupine vegetation period is shorter at higher temperatures and longer at higher precipitation levels.