Seasonal variation on chemical parameters of well water at Draa Lasfar region (Marrakech, Morocco) was studied. A total of 144 samples were collected between 2012 and 2013 and were analyzed for temperature (T°), pH, total hardness (TH), chemical oxygen demand (COD), nitrates, Cd, Pb, and Zn. Significant difference between seasons was observed for these parameters. Highest temperature (28.72±3.16) was recorded during summer. COD and Zn concentration was recorded maximum during summer (167.25±31.05 mg/l, 131.4±12.0 µg/l respectively). Highest nitrates (2.67±0.75 mg/l) concentrations were recorded during spring. Highest Pb (632.14±82.54 µg/l) and Cd (1.93±0.36 µg/l) concentrations were recorded during winter. Alternating seasons can be likened to small-scale climate change. Therefore, the impacts of this change on quality of water resources include particularly the modification of parameters values. The main drawn conclusion is that a degradation trend of well water quality in the context of climate change can lead to an increase of at-risk situations related to potential health impact.