Official Met Office and BBC Weather forecasts establish a 17°C daytime maximum for London on June 6, 2026, under unsettled post-May conditions featuring light rain, moderate south-westerly winds, and limited solar heating that suppressed further warming. Ensemble model runs show tight clustering around this value, consistent with climatological norms for early June following the prior month’s heatwave. Trader consensus at 100% implied probability for the 17°C outcome reflects this high-confidence guidance from authoritative sources, with minimal spread in observations and projections. A realistic challenge would require an unforecasted rapid clearance of cloud cover or warmer air advection, though current data and model consensus make substantial deviation before resolution highly unlikely.