The level of deep convective transport (LCT) is a critical quantity for determining the impact of deep convection on the composition of the upper troposphere and lower stratosphere (UTLS) within the Asian summer monsoon anticyclone (ASMA). Here, the LCT is estimated using high resolution balloon-borne profile measurements of water vapor obtained over Lhasa and Kunming during eleven ASM seasons. The signature of deep convection is revealed by a modal profile of near 100% saturation over ice (RHi) derived from frost-point temperature and air temperature. Analysis shows that the LCT is ~16 km (359–376 K) over Lhasa and reaches the tropopause (~17 km, 372–391 K) over Kunming. Deep convection frequently reaches above the center of the ASM anticyclone (150 hPa or 14 km), allowing upward transport into the stratosphere, whereas earlier satellite studies suggested a much lower top altitude for deep ASM convection.