The experimental IR-PD (infrared predissociation) spectra of Li⁺(H₂O)_3–4Ar and Li⁺(H₂O)_3–4 clusters, monitoring two different loss channels and thus different temperatures, have been reanalyzed using DFT-MD (density functional theory based molecular dynamics) simulations for finite temperature and anharmonic theoretical spectroscopy. The use of DFT-MD to calculate IR-PD spectra at low and elevated temperatures was found remarkably accurate and useful in precise structural characterization. The dynamical spectra have in particular provided the opportunity to estimate the clusters temperatures in the IR-PD experiments. The temperatures for Li⁺(H₂O)_3–4Ar are estimated at 50–60 K whereas Li⁺(H₂O)₃ and Li⁺(H₂O)₄ have been estimated at around 500–600 and 400 K, respectively.