At finite temperatures, nuclear excitations are significantly modified, most notably through the emergence of additional low-energy dipole strength, which can critically impact astrophysical reaction rates. Ongoing fusion-evaporation experiments on Ni isotopes provide a unique opportunity to investigate the hot pygmy dipole strength (HPDS), underscoring the need for reliable theoretical predictions and a comprehensive understanding of this emerging phenomenon. In this work, the HPDS is investigated in Ni isotopes from $N=Z$ to neutron-rich systems (${}^{56–70}\mathrm{Ni}$) over a temperature range of $T=0\text{–}2$ MeV using the finite-temperature relativistic quasiparticle random-phase approximation (FT-RQRPA). In neutron-rich Ni isotopes, the pygmy dipole strength at higher temperatures exceeds by up to 2.5 times its value observed at zero temperature. In contrast, near $N\approx Z$, isotopes show negligible low-energy dipole strength at $T=0$ MeV but develop a pronounced HPDS as the temperature increases. Predicted $E1$ energy-weighted strength ($S_{\text{EWS}}$) and cumulative $B\left(\mathrm{E}1\right)$ values for HPDS are presented across the Ni isotopic chain for various low-energy intervals and temperatures, providing essential benchmarks to support and guide experimental studies.

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• Collective levels
• Electromagnetic transitions
• Nuclear structure & decays
• 59 ≤ A ≤ 89