Evolution of the flux and hardness ratio of Swift J1727.8−1613. The photon flux in the 2–20 keV range is shown in the upper-left panel. The hardness ratio, i.e. the ratio of the photon flux in the 4–10 and 2–4 keV bands, is shown in the lower-left panel. The fluxes are the 3-day averages from MAXI. The hardness-intensity diagram (right) goes from the beginning of the outburst until 2024 April 22. We indicate the initial five observations in the hard and intermediate states by IXPE (described in detail in Veledina et al. 2023; Ingram et al. 2024) as black stars, labelled 1–5. The two observations in the soft state (described in detail in Svoboda et al. 2024) are marked by the red triangles, labelled 6 and 7. The new IXPE observation in the dim hard state, reported in this paper, is marked by the blue diamond symbol and labelled 8.