[Objectives]  To investigate the effects of temperature and humidity on the population dynamics of Grapholita molesta, a pest that causes significant losses to pear crops worldwide. [Methods]  A monitoring site was set up in a pear orchard in Daxing, Beijing municipality where sex pheromone traps were used to monitor the population dynamics of adult G. molesta over three years (2018-2021). The data obtained were combined with local meteorological data collected over the same period to analyze the relationship between temperature, humidity and population dynamics. [Results]  G. molesta began to appear in the pear orchard in mid to late March. Four population peaks occurred each year; in mid to late April, mid-June, mid to late July and early to mid-September. There was a significant relationship between the average and maximum temperature and population density, which can be described by the equation Y=﹣5.62﹣0.16X₁+0.72X₂+0.52X₃+0.18X₄, where X₃ is the highest temperature, X₁ is the average temperature, X₂ is the lowest temperature and X₄ is the average relative humidity. The relative importance of these factors was: X_3> X_1> X_2> X₄. [Conclusion]  There is a significant relationship between the occurrence of G. molesta in pear orchards in Daxing, Beijing municipality, and local temperature and humidity data. These results lay a foundation for developing a model to predict the occurrence of G. molesta.