Trader consensus for London May precipitation shows closely matched probabilities for the 10-15 mm and 15-20 mm ranges because recent atmospheric conditions have produced intermittent light showers without sustained wet spells. The North Atlantic jet stream's variable positioning, combined with occasional high-pressure blocking, has kept totals near the lower end of historical variability for the first half of the month. Official Met Office observations and ensemble models highlight genuine uncertainty in how Atlantic fronts will evolve over the remaining weeks, with small shifts in steering patterns or sea-surface temperatures capable of pushing accumulations higher or keeping them suppressed. New forecast updates and rainfall measurements will continue to refine these market-implied odds as the month progresses.