London, United Kingdom · 51.51°
Oedema in London
3707 hours in an average year meet every threshold this disease needs in London, peaking in December. Those add up to about 120.2 sustained favourable spells a year, and it is the spells rather than the scattered hours that lead to infection.
Risk in London, next 48 hours
When conditions favour it in London
Hours in an average month when conditions meet every threshold this disease declares (2021–2025). Faded bars are months the database does not list the problem as active.
This disease's thresholds: ≤18°C · humidity ≥85%. Every hour in the archive was tested against them.
These come from the ERA5 reanalysis on a roughly 9 km grid, so they describe the area rather than your plot. A shaded, sheltered corner holds leaf wetness longer than open ground, so conditions there can favour it more often than the figure suggests. This is a climate profile, not a forecast — the panel above carries the current risk.
How this compares
Of the 13 locations published here, London ranks 3 for hours favouring this disease in a year.
Fix the cause, not the leaf
No spray will help here. The trigger is soil, water supply, nutrition or temperature, so change the growing condition and judge the result on new growth, not on damaged leaves.
Scout the planting once temperatures drop below 18°C, with humidity above 85%. Risk builds after roughly 12 unbroken hours of those conditions, so the morning after such a night is the moment to look.
Not contagious. Nothing spreads from plant to plant here. Neighbouring plants showing the same signs are reacting to the same soil, water or weather, so fix the cause rather than isolating plants.