Met Office observations from London City Airport and Heathrow Airport—the key stations for this market—confirm the highest temperature on April 19 reached exactly 15°C amid persistent low cloud cover and cool northerly winds that suppressed daytime heating. This aligns with trader consensus at nearly 100% implied probability, reflecting verified hourly data rather than forecasts, following a sharp cooldown from early April's record 26.6°C peak on the 9th under high pressure. Scenarios challenging this would require rare post hoc data revisions from official sources, such as equipment recalibrations, though such adjustments are exceedingly uncommon for settled daily maxima. No further updates expected as the market nears resolution.