Balloon-borne measurements of ozone vertical distribution and meteorological parameters are presented for a complete seasonal cycle (2011) for the first time, from a high altitude site Nainital (79.5oE, 29.4oN, 1958 m amsl) in the central Himalayas. Balloons, carrying an ozonesonde (EN-SCI 2ZV7 ECC) and a radiosonde (iMet-1-RSB 403 MHz GPS) were launched with a frequency of 3-4 flights per month which resulted in a collection of total 48 profiles during 2011. Maiden observations revealed large variabilities in the ozone distribution and meteorological parameters. Tropopause pressure is estimated to be ~100 hPa from the radiosonde observations and is in agreement with the satellite (AIRS and TES) and model (WRF) results but shows dramatic variability (150-250 hPa) during winter and early spring. Relative humidity in the lower troposphere is highest (80-100%) during summer and is attributed to the arrival of monsoon. Occasionally observed very high wind speed (~40 to 80 m/s) in middle-upper troposphere, particularly during winter, is suggested to be associated with the subtropical jets. Lower tropospheric (2-6 km amsl) ozone shows a prominent seasonality with highest levels during spring (~70-110 ppbv in May) and lowest levels during summer-monsoon (~20-50 ppbv), which is consistent with the surface observations and satellite data over this region. However, ozone seasonality is less pronounced in the middle-upper troposphere. A prominent feature of secondary ozone peaks have been observed on several occasions in the middle-upper troposphere more frequently during spring. Springtime ozone profiles are classified into high and low fire activity periods using MODIS fire counts and influence of biomass burning is estimated to be 19.9±4.6 ppbv in 2 to 4 km altitude range. Regional photochemistry is suggested to be the key process during spring with a significant contribution from the north-Indian biomass burning. Dynamical processes including advection and stratospheric intrusions play key roles except during summer-monsoon. Ozonesonde profiles with the TES operator are shown to be in good agreement with the collocated satellite (TES) retrievals. Estimated tropospheric column ozone show differences between the ozonesonde and TES during winter and is shown to be associated with the tropopause variability. These observations form invaluable datasets for the validation of satellite and model results, which is severely lacking over this region so far.