Vertical, horizontal, and temporal changes in temperature in the Atlantis II and Discovery hot brine pools, Red Sea

► Maximum temperatures are 68.3 °C in Atlantis II Deep and 45.0 °C in Discovery Deep. ► Temperature of all convective layers increased since the 1960s at the same rate. ► Heat is lost from the brine pools to overlying Red Sea Deep Water. ► New upper brine layer at 1900-1990 m appeared sometime between 1976 and 1992. ► Hydrothermal heat flux decreased since 1966 from 0.54 GW to 0.18 GW.