**Recent model consensus from the Met Office and other forecasts points to overnight radiative cooling under clear skies and light winds as the main factor favoring a London minimum of 13–14 °C on 23 August 2026.** After a warmer-than-average early August that included a 37.7 °C peak, high pressure has settled over southern England, producing dry, mostly clear conditions that allow efficient heat loss after sunset. Official guidance lists a nighttime low near 14 °C, with some ensemble runs and private models showing 12–13 °C if dew-point depression and minimal cloud cover persist through the early morning. Traders have priced the 13 °C outcome highest because it matches the central tendency of current runs while accounting for typical forecast uncertainty ranges of ±1–2 °C this far ahead of the verifying observation. The modest probability on 12 °C reflects the small chance of slightly stronger cooling if winds stay lighter than expected; probabilities drop sharply above 15 °C or below 11 °C because those outcomes would require meaningful departures from the current stable pattern. No major model shifts have occurred in the past 48 hours, keeping implied probabilities anchored to the latest guidance ahead of the final overnight verification.