The annual cycle of precipitation is a fundamental aspect of the global water cycle. Climate warming induces amplitude enhancement and phase delay in the zonal-mean tropical precipitation. Here, we report a land-ocean contrast in the phase response of precipitation annual cycle, with a delay over land and an advance over ocean as climate warms. Although two-thirds of the Earth’s surface are covered by ocean, land dominates the zonal-mean phase delay, attributable to an increase in the effective atmospheric heat capacity. The phase advance over ocean is associated with a precipitation shift from land to ocean during the peak rainy season. This shift is well constrained by the energetic and related to a land-ocean contrast in the amplitude change of surface temperature annual cycle: seasonally different wind changes enhance this amplitude over ocean, while increased effective atmospheric heat capacity and surface cooling feedback reduce the amplitude over land.
