Recent Met Office and ECMWF model consensus points to a mild overnight period for London on May 20 driven by southerly airflow and reduced cloud cover, which has elevated the 17°C-or-higher outcome to 37.5% implied probability while keeping 13°C and 12°C as the next most favored bins at 26% and 20.5%. Persistent high pressure over northern Europe is steering warmer air masses northward, pushing expected minimums above the seasonal average of roughly 9°C, yet residual Atlantic moisture maintains a 19.5% chance of a sharper drop to 7°C or below if showers develop. Forecasters continue to monitor the 18–22 May update cycle, as any shift in steering patterns or increased nocturnal cloud could quickly compress probabilities toward the 11–14°C cluster currently trading between 16.5% and 19%.