Persistent subtropical high pressure and an entrenched heat dome over the southern U.S. are sustaining above-normal overnight lows across central Texas, positioning upper-70s readings as the dominant outcome for Austin’s minimum temperature on August 23. National Weather Service forecasts and recent model guidance indicate lows near 79–80°F under mostly clear skies and light southerly flow, with limited radiative cooling from elevated dew points and compressional warming. This aligns with the ongoing Heat Advisory and above-average August conditions driven by the ridge, while historical normals near 73°F reflect rarer cooler nights absent such blocking patterns. No frontal systems or significant moisture intrusions are expected to alter the trajectory before resolution.