Hemispherically-averaged day side and night side temperatures T_d, T_n in Spitzer Channel 1 (red squares) and Channel 2 (black circles) as a function of planetary equilibrium temperature. These temperatures are derived by averaging the day side and night side temperature maps derived from the full phase curve fit. The hottest planet is KELT-9 b, which clearly breaks the apparent “uniform night side temperature” trend among cooler hot Jupiters noted by Keating et al. (2019). Uncertainties are smaller than the points.