Post-frontal warming after a strong cold front that swept across South Africa in the preceding days is the main driver behind the Polymarket distribution favoring 26–28 °C maxima in Cape Town on August 13. Recent South African Weather Service and global model guidance point to a moderating Atlantic high and reduced onshore flow that should permit daytime temperatures to climb into the mid-20s amid typical winter variability. Historical August averages near 18 °C provide context for the upside potential, while spread across outcomes reflects model divergence on exact peak values and timing of any residual cloud or wind effects. Traders are weighting the 27 °C bin highest because it aligns with the current consensus range, though shifts in steering patterns or late adjustments to the high-pressure ridge could readily move the realized maximum by 1–2 °C.