Recently calculated potential energy curves for the krypton dimer cation [R. Kalus et al., Chem. Phys. 294 (2003) 141] are augmented by accurate ab initio calculations of transition dipole moments and used in diatomics-in-molecules modelling of Kr n + (n=2-5) photoabsorption spectra at both zero and non-zero temperatures. Several models of intra-cluster interactions in Kr n + are used. In addition to a standard diatomics-in-molecules model, the spin-orbit coupling is taken into account through a semi-empirical treatment and the most relevant three-body forces are represented by induced dipole-induced dipole polarization interactions. The transition dipole moments are calculated for n>=3 within the point-charge approximation with inclusion of the polarization effects. The results are compared with available experimental data. A reasonable agreement is found.