.A field experiment was conducted at Entomology farm, Faculty of Agriculture, SKUAST-K during rabi, 2019-20 to study the population dynamics of Thrips tabaci Lindeman in onion. The incidence of adults (31.00/ plant) and immatures (61.00/ plant) was observed from 9th standard meteorological week (SMW). It reached a peak on 22nd and 21st SMW and declined thereafter. The incidence revealed a positive correlation with temperature, rainfall and evening RH, and a negative one with morning RH; however, with nymphs it was a positive one with temperature and evening RH, and a negative one with rainfall and morning RH.