Recent Met Office guidance highlights a transitional pattern for early August, with residual high pressure giving way to more changeable Atlantic influences that introduce forecast spread in London’s nocturnal minimum. Ensemble model runs diverge on the timing and strength of any incoming fronts or cloud breaks, directly affecting radiative cooling rates and thus the precise overnight low. This uncertainty underpins the tightly clustered market-implied odds around 18–20 °C, each near 36 %, while lower probabilities for 15 °C or below reflect the prevailing above-average temperature baseline driven by warm sea-surface conditions. Short-range updates from the Met Office and ECMWF over the next 48 hours will likely narrow the range ahead of resolution.