More than 40 per cent of Edinburgh's expected monthly rain fell in the space of three hours during Wednesday's heavy downpours in the Capital.
Met Office meteorologist Mark Wilson said 38mm of rain was recorded at the Met Office Gogarbank weather station between 4pm and 7pm. The monthly rainfall expected for all of August in parts of eastern Scotland, including Edinburgh, is 91mm.
And Mr Wilson said other weather stations may have recorded even higher rainfall totals in other parts of the city.
A Network Rail spokesman also said that 60 per cent of the month's predicted rain fell in the Winchburgh area in a two-hour period, causing the track to become waterlogged and disrupting train services between Glasgow and Edinburgh.
The figures have emerged after heavy rain and flooding caused major disruption in the Capital on Wednesday and into Thursday, with roads closed due to flooding, bus and train services disrupted, businesses closing and even a church being evacuated due to a lightning strike.
A yellow "be aware" warning for rain is in place for Edinburgh - and much of Scotland - all day on Friday.
A thunderstorm warning will then be in place from midnight on Saturday until 6am on Sunday morning.
Mr Wilson said there is the potential to exceed the August average rainfall figure of 91mm by the end of Sunday, adding: "We have had 38mm of rain already so it has the potential to exceed the monthly average."
He said latest spell of bad weather is being caused by a deep area of low pressure containing warm air coming from the Southern Atlantic which is carrying lots of moisture.