Recent meteorological observations and forecast model runs from sources such as the Met Office confirm a daytime maximum near 20°C in London on October 13, 2026, under mild southwesterly flow with limited cloud cover and light precipitation. This alignment of real-time station data and short-range guidance has driven near-certain market-implied odds on 20°C. Historical October averages hover around 16°C, underscoring the mild anomaly, while resolution hinges on official recorded highs at representative sites. Only an unforeseen late surge above 21°C or station-specific measurement variance could realistically alter the outcome at this stage.