The hyperfine field, ${H}_{\mathrm{hf}}(T)$, in polycrystalline CuO has been studied by $^{57}\mathrm{Fe}$ M\"ossbauer-source spectroscopy (MS), ${\ensuremath{\mu}}_{+}$ spin rotation $\ensuremath{\mu}\mathrm{S}\mathrm{R}$, and $^{100}\mathrm{Rh}$ perturbed angular correlation (PAC) over $4\mathrm{K}lTl295\mathrm{K}$. Antiferromagnetic order is observed below ${T}_{N}=226(1)$ K. MS and PAC each exhibit a single dominant site with no $K$-capture aftereffects while $\ensuremath{\mu}\mathrm{S}\mathrm{R}$ has five components. For $\ensuremath{\mu}\mathrm{S}\mathrm{R}$ and PAC ${H}_{\mathrm{hf}}(T)$ is well approximated by spin $S=\frac{1}{2}$ mean-field theory; for MS it is anomalous, indicating a significant difference in spin between Fe and Cu and/or moment coupling for Fe-Cu and Cu-Cu. There is no evidence for long-range dynamic correlations, as observed for ${\mathrm{La}}_{2}$Cu${\mathrm{O}}_{4}$.