Current trader consensus around 15–30 mm total precipitation for London this May reflects below-average rainfall through mid-month, with only about 17 mm recorded so far against a climatological normal of 46–57 mm. High-pressure dominance and limited Atlantic moisture advection have suppressed widespread showers, consistent with recent Met Office guidance favoring drier conditions over the next two weeks. Remaining uncertainty between the tightly matched 15–20 mm and 25–30 mm bins stems from potential short-wave troughs that could deliver isolated convective bursts, though ensemble forecasts show low confidence in totals exceeding 25 mm. Historical analogs from drier Mays underscore how steering patterns and sea-surface temperatures can keep monthly accumulations well below average.