Before, during, and after a wellbore cementing operation temperature, pressure, and other conditions of a cement slurry are monitored downhole. The monitored conditions are compared to theoretical or calculated conditions to confirm the cementing operation is carried out in downhole conditions as planned. When differences between the monitored conditions and those used in planning the cementing operation exceed an acceptable range, adjustments are made to the cementing operation to account for the differences. The adjustments include changing a composition of the cement slurry to increase its design temperature, wellbore intervention if monitored pressure reveals a backflow of cement, and proceeding with another cementing stage if the monitored conditions indicate the cement slurry has cured into a set cement.