Study was conducted during 1988-91 at Faisalabad to determine the role of temperature, relative humidity, rainfall and wind velocity in fluctuating aphid density in wheat. Fluctuation in pest population varied in different years. It was higher in 1988-89 and lower in 1990-91. Maximum aphid population was trapped in March. Wind velocity played a positive and significant role in fluctuating aphid density during 1990-91 (r = 0.798). All other factors for the years individually had no significant correlation with aphid density. However, multiple regression showed a significant trend between aphid density and weather factors for 1990-91. The contribution was 86.6 percent. Regression analysis for 1988-89 and 1989-90 did not respond significantly showing 16.00 and 33.40 percent contribution in fluctuating aphid density.