Over the last few years, particular attention has been given to climate change and its impacts on water resources and agriculture. This study focuses on analyzing the effects of rainfall and temperature variability on cereal production in the Tiaret region (Western Algeria) and evaluating the future climate change and its impact on cereal yields. First, we analyzed the temporal variability of mean rainfall, mean temperature, minimum temperature, and maximum temperature of the Tiaret meteorological station and cereal yield variability using the Pettitt test and Pearson correlation coefficient. The second step consisted of evaluating the effect of future climate change on average yield using simulated data from the Africa-Cordex regional climate model during two projected periods, 2021–2050 and 2071–2099, under two scenarios: RCP 4.5 and RCP 8.5. The Pearson coefficient correlation showed a significant positive correlation between yields and mean rainfall and a negative significant correlation with maximum temperature. The Pettitt test highlighted a decrease of 30% in annual rainfall and an increase of 1.3 °C in maximum temperature. On a monthly scale, a decrease of about 50% in rainfall is observed in April and May, with an increase of about 2 C in maximum temperature for the same months. Future average yields are estimated by linear regression with rainfall and temperature. By the end of the century, RCM projections show a decrease of 36% in rainfall and an increase of 3.9 °C under RCP 8.5. Based on these results, yields will drop by 20% if no adaptation measures are undertaken. Changes in rainfall and temperature significantly affect the phenological stages of crop development. Therefore, to ensure the country's food security, adaptation strategies are necessary to address the negative impacts of climate change. Otherwise, the cereal import bill may increase to meet the needs of a growing population.