This paper presents and discusses the results of the transient heating analysis of single core cables laid directly in the ground. In order to analyze transient heating of cables a daily load diagram with three levels, which can be described by two parameters is used. These parameters are duration of high level loading and load factor. In order to analyze daily temperature variation of the cable the ratio of high level current loading to rated current of the cable is also required. Parameters that affect results are varied in analysis: thermal conductivity and diffusivity of soil, the distance between adjacent cables, temperature of referent soil, cross-bonding of metal sheets, etc. The results of analysis are ranges of conductor temperature variation, i.e. daily minimum and maximum temperature of the conductor for different laying and ambient conditions. The presented results can be used in estimation of cable overloading capability as well as for estimation of aging of cables exposed to cyclic loading