Official Met Office hourly observations from London stations, including Greater London sites, confirm the highest temperature on April 17 reached 18°C, peaking around mid-afternoon amid persistent cloud cover and light winds that capped daytime warming. This aligns with pre-event forecast model consensus from the UK Meteorological Office, predicting mild highs of 16–18°C after an unusually warm early April spell featuring 26°C peaks. Trader consensus at 100% implied probability for 18°C reflects verified observational data from authoritative stations like those near Heathrow and City Airport, backed by real capital in the market. Realistic challenges would require rare post-resolution data revisions from official sources, though current records show no discrepancies across proximal monitoring points.