**High pressure and a moderating westerly flow are keeping London's peak temperature tightly contested between 25–26°C on August 7.** Official Met Office guidance projects a 25°C maximum under sunny intervals after early cloud, with a strengthening breeze limiting further warming. Recent days saw 29°C on August 4 under clearer, warmer southerly air, but the shift to fresher Atlantic flow has trimmed extremes while still allowing strong insolation to push readings into the mid-20s. Ensemble forecasts show only modest spread, with most runs clustering near 24–27°C; small differences in cloud timing, boundary-layer mixing, or exact high-center position determine whether the urban heat island adds the extra degree to reach 26°C. Historical August baselines for London sit around 22–23°C, so current conditions remain above average yet far from heatwave thresholds. With resolution just 48 hours away and limited new model runs expected before the peak, trader prices reflect genuine uncertainty between these two adjacent bins rather than a single dominant outcome.