There is an apparent mismatch between electron paramagnetic resonance and M\"ossbauer spectroscopy results on the charge and spin states of dilute Fe impurities in NaCl; M\"ossbauer spectroscopy data have been interpreted in terms of high-spin ${\mathrm{Fe}}^{2+}$, while electron paramagnetic resonance studies suggest low-spin ${\mathrm{Fe}}^{1+}$. In the present study, the charge and spin states of dilute substitutional Fe impurities in NaCl and LiF have been investigated with $^{57}\mathrm{Mn}\ensuremath{\rightarrow}^{57}\mathrm{Fe}$ emission M\"ossbauer spectroscopy. A scheme is proposed which takes into account the effects of nearest-neighbor distances and electronegativity difference of the host atoms on the M\"ossbauer isomer shift and allows for the unequivocal differentiation between high-spin ${\mathrm{Fe}}^{2+}$ and high/low-spin ${\mathrm{Fe}}^{1+}$ in M\"ossbauer spectroscopy. From these considerations, the M\"ossbauer results are found to be consistent with dilute Fe impurities in NaCl and LiF in a low-spin ${\mathrm{Fe}}^{1+}$ state. These conclusions are supported by theoretical calculations of isomer shifts and formation energies based on the density-functional theory. The experimental results furthermore suggest that charge compensation of dilute ${\mathrm{Mn}}^{2+}$ dopants in NaCl and LiF is achieved by Na vacancies and ${\mathrm{F}}^{\ensuremath{-}}$ interstitials, respectively.