These studies were conducted at Daphar (Mandi Baha-ud-Din) and Bahawalpur during 1997-2005 and at Ayub Agricultural Research Institute, Faisalabad, Pakistan during 1999-2005 to determine the role of temperature and relative humidity in fluctuating aphids density in wheat crop. Moericke yellow water traps were used for monitoring alate aphids. The results revealed that pest population varied in different years. The highest population (347.24/tray) was observed at 20.20 degree C and 59.55 percent RH at Faisalabad during 2003-04. The lowest population (5.84/tiller) at 13.37 degree C and 78.17 percent RH was noted at Daphar during 1997-98. Temperature at Daphar showed positive and significant correlation (0.394**) with alate aphids while RH at Faisalabad and Bahawalpur showed significant correlation with r-values of - 0.642** and 0.369**, respectively. On cumulative basis, temperature and relative humidity contributed 12.1 and 4.8 percent role in population change, respectively. The study will provide guideline to extension workers for undertaking plant protection measures to avert higher pest losses in wheat yield with better socio-economic impact on farming community.