**Elevated overnight minimums amid a persistent Southern California heat wave are the dominant driver of trader positioning for Los Angeles’s August 25 low temperature.** Official National Weather Service guidance and model consensus indicate highs of 96–99 °F downtown with limited nocturnal cooling, keeping lows near or above 70 °F as strong subsidence and warm advection suppress the usual marine layer. Historical August averages hover around 66 °F, but recent observations show minima stuck at 68–71 °F; the current airmass raises the probability of another warm night while still allowing a marine push or clearer radiative cooling to produce readings in the mid-60s. This genuine forecast spread—between record-level warmth and more typical late-summer recovery—explains the near-even market split between the lowest and highest bins and the clustering around 68–77 °F outcomes. New model runs and marine-layer updates over the next 24 hours will be the key catalysts for any shift in implied probabilities.