Recent official forecasts from the Met Office and BBC Weather point to a minimum of 15–16°C in London on August 18, 2026, driven by an incoming Atlantic front bringing light rain, increased cloud cover, and westerly winds that limit nocturnal radiative cooling while suppressing daytime maxima near 25–26°C. This pattern follows a warmer spell and aligns with mid-August climatology, where average lows hover around 14–15°C amid typical maritime influence. Ensemble model spreads introduce uncertainty, with clearer interludes in some runs potentially supporting overnight minima of 17–19°C; trader consensus clusters on these outcomes (implied probabilities of 21–38.5%) as they reflect the balance between forecast guidance and historical variability in boundary-layer temperatures. Updated model runs and observational data from the next 48 hours will refine resolution thresholds for this short-range market.