What conditions of temperature and pressure do real gases differ most from ideal gases?

Real gases diverge most from ideal gases at high pressures and low temperatures. Under high pressure, gas molecules are forced closer together, leading to intermolecular forces and deviations from ideal behavior. Conversely, at low temperatures, kinetic energy decreases, and attractions between molecules become more significant, further causing deviations from the ideal gas law. Thus, the conditions where real gases differ most from ideal behavior are characterized by high pressure and low temperature.