Seasonal Evolution of Saturn's Polar Temperatures and Composition

•Record of seasonally evolving polar temperatures and composition reconstructed from a decade of CIRS measurements.•Warm polar cyclones within 2–3° of each pole are persistent features irrespective of season.•Southern summer stratospheric hood has disappeared; slow warming evident in the north.•Fast T changes at the pole suggest vertical motions plus stratospheric aerosol contributions to the radiative budget.•North polar minimum T 6–8 years after winter solstice, south polar maximum T 1–2 years after summer solstice.