The extinction response of strained, atmospheric, premixed methane/air flames was studied experimentally and numerically in the presence of chemically inert particles. The experiments were conducted in normal- and micro-gravity using the opposed-jet configuration and by seeding the particles from the bottom burner. The numerical simulations were conducted by solving the conservation equations of mass, momentum, energy, and species with detailed descriptions of chemical kinetics, molecular transport, and thermal radiation for both phases, along the stagnation streamline of the counter-flow. The experimental data were compared with numerical simulations and insight was provided into the effects of equivalence ratio, strain rate, heat loss, particle size and type, gravity, and flame configuration. It has previously shown experimentally and numerically that for low strain rates larger particles can cool the flames more efficiently compared to smaller particles. Numerical simulations have further shown that this trend is reversed at high strain rates. This prediction was experimentally confirmed in the present study, which also revealed that the crossover point depends not only on the particle size but also on the equivalence ratio of the gas-phase. The micro-gravity experiments, the first ones to be ever conducted for dusty flows, were carried out on board the KC-135 aircraft. The experimental results confirm that the cooling effect of the particles is more profound in the absence of gravity. However, it was found that the effect of gravity on the flame cooling is not caused only by the effect that the gravitational forces have on the particle motion, as one would expect, but also on the effect of those forces on the particle number density distribution. Finally, comparisons between experimental and predicted extinction states were performed for the first time, revealing a close agreement given the various simplified assumptions that are associated with the numerical model.