Temperature difference as a function of the atmospheric parameters in Table 2 and the angular diameter in Table 1. The plots include the Gaia benchmarks (see Fig. 7 of Paper I). The stars for which were derived in this work can be identified by their labels in the top and bottom panels. The stars are colour-coded according to the method used to infer their standard T_eff in the literature: direct application of interferometry (red), indirect interferometry based in colour calibrations (blue), and IRFM (grey). The symbol sizes are inversely proportional to the log ɡ values. The two temperature measurements of HD 175305 (see Table 1) are connected by a vertical dashed line. The red (dashed grey) line at −11 K (+28 K) indicates the median of the differences between Hα temperatures and those derived from interferometry (from IRFM), computed omitting HD 221170, HD 175305, and HD 2665. Their dispersion of 42 K (46 K) is indicated by the error bar with the same colour.