Variation in grain, semolina, dough strength, and pasta quality traits were evaluated using the effect of genotype and weather factors (air temperature, rainfall, and relative humidity). In addition, size exclusion high performance liquid chromatography (SE-HPLC) was applied to determine the correlation between quality traits and protein molecular weight distribution (MWD) with cooked firmness and cooked weight of fresh pasta made from four durum wheat genotypes. Results indicated that the environment was a great source of variation in the majority of quality traits such as test weight, 1000-kernel weight, grain protein content, vitreous kernel content, falling number, semolina protein content, semolina extraction rate, pasta color, and pasta cooking quality traits. However, grain yellow pigment content, semolina yellowness (b* value), gluten index, and mixogram time-to-peak were mainly affected by genotype. High air temperature and days with temperature ≥ 30 °C were desirable for high protein content and high pasta cooking quality. Ideal growing locations to achieve the greatest falling number, vitreous kernel content, gluten index, and high pasta color were favored by low relative humidity and low rainfall. Days with temperature ≤ 13 °C favored high 1000-kernel weight and test weight. In addition, damp conditions such as high relative humidity favored 1000-kernel weight and semolina extraction rate. Protein content and its fractions had a predominant role on the variation of fresh pasta cooked firmness and cooked weight, while gluten index did not relate to cooking quality. The quantitative increase in extractable monomeric protein (gliadins) was associated with a decline in cooked firmness, while it enhanced cooked weight. The possible gel forming properties of some protein fractions, including albumin + globulin during cooking were associated with high cooked firmness, low cooked weight, and low cooking loss in fresh pasta. Genotypes differed in their genetic potential for quality traits evaluated and in the magnitude of their response to the environment. A trait is defined as stable when it is not greatly affected by the environment. Stable traits are necessary in order to have consistency in crop quality across years and growing locations.