A recently proposed CMB temperature relation, obtained from applying the Stefan Boltzmann law to the Hubble sphere and from related Hawking–Planck–Hubble scale arguments, may be written in the compact form TCMB(t) = TP/(8π √(NP(t))). Here NP is the effective Poisson-shot count. In an RH = ct cosmology, the normalization consistent with the Stefan–Boltzmann radiation density is NP(t) = (RH(t))/2lP = t/2tP = (Mc(t))/mP, where Mc(t) = c2RH(t)/(2G) is the critical Hubble mass. If instead one defines the doubled Hubble-sphere mass Mu(t) = c2RH(t)/G, then Mu/mP = 2NP. The formula has the mathematical structure of a Poisson relative-fluctuation law, since σN/N = 1/√N for a Poisson count, and may equivalently be written TCMB(t) = TP/8π σNP/NP.We call this the Poisson-shot CMB formula. Substitution back into the Stefan–Boltzmann law gives uγ ∝ TCMB4 ∝ RH-2, matching the critical-density scaling in RH = ct and yielding a constant photon radiation density parameter. This provides additional blackbody support for the formula and connects it to the observed near-perfect blackbody spectrum of the CMB. By contrast, in the standard ΛCDM framework the present CMB temperature is normally an observational input: the model predicts the redshift scaling T(z) = T0(1 + z) once T0 is supplied, but it does not derive the absolute present value T0 from the Planck scale and the Hubble scale.