Using observed wind and water vapor data from June 2006, water vapor exchange between the Rongbuk Valley and its above atmosphere is estimated for the first time. The water vapor level shows a high value from 23?29 June and a low from 12?21 June, which coincide with the South Asian summer monsoon (SASM) active and break stages, respectively. The water vapor can be strongly injected into the closed region of the Rongbuk Valley from the outside atmosphere, with an average strength of 0.4 g s?1 m?2 in June 2006, given that no evaporation occurred. The air moisture exchange processes can be greatly affected by the SASM evolution through changes in local radiation forcing.