The effects of matter-enhanced neutrino oscillations on solar-neutrino experiments can be calculated accurately only if uncertainties in the standard solar model are treated properly. As the oscillation probability depends on the neutrino energy, while modifications in the parameters of the standard solar model produce correlated changes in the various solar-neutrino sources, Monte Carlo calculations appear to offer the only means for addressing this problem. We consider the effects of matter-enhanced neutrino oscillations for 1000 standard solar models that were constructed by varying the solar input parameters according to their estimated probability distributions. From these Monte Carlo calculations (carried out for a neutrino parameter grid of 10{sup 4} cases corresponding to 3{times}10{sup 8} separate Mikheyev-Smirnov-Wolfenstein (MSW) calculations) we derive 95%-C.L. limits on the neutrino mass difference {delta}{ital m}{sup 2} and mixing angle sin{sup 2}2{theta} for possible outcomes for the {sup 37}Cl, {sup 71}Ga, and Kamioka II experiments and the assumption of two-flavor oscillations.