As part of our systematic study on physicochemical characterization of ionic liquids, we carried out new measurements of electrical conductivity for aqueous solutions of four ionic liquids at normal atmospheric condition for temperatures up to 353.2 K. The ionic liquids considered were 1-butyl-3-methylimidazolium chloride [Bmim][Cl], 1-butyl-3-methylimidazolium bromide [Bmim][Br], 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [Bdmim][BF(4)], and 1-butyl-2,3-dimethylimidazolium hexafluorophosphate [Bdmim][PF(6)]. The electrical conductivity was measured using a commercial conductivity meter and the experimental uncertainty in the measurement was estimated to be +/- 1%. In this paper, the conductivity data are reported as a function of temperature and composition. A modified form of the Arrhenius equation was used to correlate the temperature dependence and composition dependence of the investigated ionic liquid systems, and the obtained correlations were found to be satisfactory.