The work proposed by Vadasz et al. (Transp Porous Media 103:279-294, 2014) motivated us to take up the problem of chaotic convection under temperature modulation for study. The analysis of buoyancy driven convection for moderate Prandtl number in a fluid saturated porous layer heated from below and subject to temperature modulation is presented. It has been investigated that a better combination of values of and scaled Rayleigh number provides a way for chaos. It is found that the temperature modulation (suitable choice of frequency , amplitude along with scaled Rayleigh number ) of the boundaries is to enhance the behaviour of the chaotic motion. The lower boundary plate modulation is similar to the gravity modulation given by Vadasz et al. (Transp Porous Media 103:279-294, 2014) and Bhadauria and Kiran (Int J Heat Mass Transf 84:610-624, 2015). It is also found that heat transfer results conform the results of Bhadauria and Kiran (Transp Porous Med 100:279-295, 2013, Int J Heat Mass Transf 77:843-851, 2014a, Int Commun Heat Mass Transf 58:166-175, 2014b).