Abstract <p>On 15 January 2022, the Hunga Tonga–Hunga Ha’apai (HTHH) volcano generated a large sulfur dioxide (SO₂), water vapor (H₂O), and silicate (SiO₄) ash plume that rapidly rose to a maximum height of ~ 58&#xa0;km. The GOES-17 Advanced Baseline Imager (ABI) acquired continuous, high-temporal-cadence, thermal infrared (TIR) data providing the ability to both examine precursory thermal activity and track the eruption plume’s migration. The above background temperatures began to increase on 20 December 2021, with a maximum of 7.2&#xa0;K detected on 8 January, leading up to the larger eruption on 14–15 January 2022. TIR spectral deconvolution modeling of the initial plume was performed to map the ash composition, particle size distribution (PSD), and ice formation. Several glass-rich andesite spectral endmembers provided the best match, with significant water vapor also detected, likely a result of vapor expansion driving the eruption and the source of ice formation at higher altitudes. The initial chaotic PSD became organized over time as the larger particles fell out of suspension leaving the fines plus water ice dominating as the plume drifted west. Over the next 1–3&#xa0;days of the eruption, the diffuse plumes were dominated by SO₂ and fine ash, which allowed a different modeling approach to retrieve SO₂ column density and sulfate speciation. The high-temporal-resolution ABI data provided an opportunity to couple pre-, syn-, and post-eruption thermal dynamics to understand large, water-rich submarine explosive eruptions and plume evolution. </p> Key points: <p>•&#xa0;High-temporal-resolution thermal infrared data enabled a complete analysis of the eruption.</p> <p>•&#xa0;Thermal anomalies are seen prior to the large eruption in January 2022.</p> <p>•&#xa0;Ash was tracked during the initial ~ 17&#xa0;h of the climactic explosive eruption followed by SO₂.</p>