Trader sentiment reflects deep uncertainty in total April precipitation for London, with closely matched implied probabilities around 19-20% for 50-60mm, under 20mm, and 20-30mm outcomes, driven by an exceptionally dry start—only 0.4mm recorded at Heathrow through early April (1% of the 42mm long-term monthly average per UK Met Office data). This stark deficit stems from persistent high-pressure dominance suppressing Atlantic fronts, punctuated by a record early-April heat peak of 26.5°C at Kew Gardens on April 8. Differentiating factors include forecast model ensembles from the Met Office and ECMWF showing divergent scenarios for the remaining three weeks: potential low-pressure systems delivering 30-50mm more via showers and fronts, versus prolonged dry spells if high pressure rebuilds. Watch daily updates for jet stream shifts and ensemble guidance through month's end.