Uniform-disk diameters of Betelgeuse measured in the K band and at 11 μm as a function of time. The black filled circles and the blue open circle represent the 11 μm diameters measured by Townes et al. (2009) and Perrin et al. (2007), respectively. The diamonds represent the K-band diameters from the following references. IRMA: Dyck et al. (1992). IOTA: Perrin et al. (2004). VINCI: Paper I. AMBER MR_K: AMBER medium-resolution (λ/Δλ = 1500) data from Paper I. AMBER HR_K 1: AMBER high-resolution data from Paper I. AMBER HR_K 2: present paper. The errors in the IOTA and AMBER measurements are smaller than the symbols.