This paper presents the results of estimation of ground level (10m) wind pattern at Kaiga site using ultra sonic anemometer for month of September. The study generated wind data at ground level for the month of September 2009. More than 70% of the wind is in a speed group less than 0.8m.s^-1, except during 12-18 h, and hence, cannot be measured by conventional anemometer or SODAR system. Present data clearly indicate that during September month, wind direction pattern observed at 10m height at Kaiga site measured using Ultra sonic anemometer is comparable with that observed at higher sites using conventional wind monitoring system. This data will be extremely useful for understanding lower wind speed distribution which may not be possible to be measured with conventional wind measurement systems. This data will be extremely useful for understanding the pattern of environmental distribution of atmospherically released radionuclides especially, that of tritium, through forest canopy surrounding the site.