Recent National Weather Service and model guidance point to a high near 99–100°F in Austin on September 16 under continued southerly flow and mostly sunny skies, with heat indices approaching 105–109°F. This stems from a persistent upper-level ridge maintaining above-normal temperatures several degrees above the 1991–2020 average high of 91°F. Low precipitation chances (under 10–20%) and limited cloud cover support the upper range of outcomes, though minor shifts in timing or thickness of afternoon cumulus could cap readings in the mid-90s or allow brief spikes above 101°F. Ensemble spreads remain modest two days out, keeping market-implied probabilities clustered across the 98–103°F bins.