The current study was directed to investigate the effect of temperature and humidity on insect pest complex of cotton. This study was carried out on the farmer field of a farmer of MouzaMehraywala tehsil and district Rajanpur southern part of the Punjab, Pakistan (29.1044° N, 70.3301° E) in the month of May, 2019 to November 2019. The climatic conditions of the study site were; a Rajanpur lie on 96m above sea level Rajanpur has a desert climate. During the year, there is virtually no rainfall. The average temperature in Rajanpur is 26.0°C | 78.8°F. Precipitation here is about 205 mm / 8.1 inch per year. Our results indicate that's the correlation of temperature (minimum and maximum), humidity (minimum and maximum), rainfall and weather condition (clear or cloud), it is clear that except temperature there is a positive correlation of jassid population. While among the relation of jassid with different factor there is very weak relation with jassid population regarding temperature (-0.001), the relation of humidity, rainfall and sky condition with jassid population is positive and moderate (0.520, 0.668 & 0.575 respectively), while the relation of jassid population among these factor is significant except temperature. The results indicate that's the correlation of temperature, humidity, rainfall and weather condition, it is clear that there is positive correlation of thrips population. While among the relation of thrips with different factor there is very weak relation of thrips population with temperature (.103), the relation of humidity, rainfall and sky condition with thrips population is positive and moderate (.515.751& .577 respectively), while the relation thrips population among these factor is significant except temperature. The results indicate that's correlation of temperature, humidity, rainfall and weather condition, it is clear that there is positive correlation of Whitefly population. While among the relation of Whitefly with different factors there is very moderate relation of Whitefly population with temperature (.076), the relation of humidity, rainfall and sky condition with Whitefly population is negative and moderate (-.051.-.368 & -.559 respectively), while the relation Whitefly population among these factor is significant except temperature.