Here we use a 3-D climate system model to study the habitability of Earth-like planets orbiting in circumbinary systems. A circumbinary system is one where a planet orbits around two stars simultaneously, resulting in large and rapid changes to both the stellar energy distribution and the total stellar energy received by the planet. We find that Earth-like planets, having abundant surface liquid water, are generally effective at buffering against these time-dependent changes in the stellar irradiation due to the high thermal inertia of oceans compared with the relatively short periods of circumbinary-driven variations in the received stellar flux. Ocean surface temperatures exhibit little to no variation in time, however land surfaces can experience modest changes in temperature, thus exhibiting an additional mode of climate variability driven by the circumbinary variations. Still, meaningful oscillations in surface temperatures are only found for circumbinary system architectures featuring the largest physically possible amplitudes in the stellar flux variation. In the most extreme cases, an Earth-like planet could experience circumbinary-driven variations in the global mean land surface temperature of up to ~5 K, and variations of local daytime maximum temperatures of up to ~12 K, on monthly timescales. Still, habitable planets in circumbinary systems are remarkably resilient against circumbinary driven climate variations.