The UK was struck by lightning between 15,000 and 20,000 times as the "mother of all thunderstorms" rolled across southern England overnight.
The London Fire Brigade (LFB) said it had taken more than 500 weather-related calls as the humid bank holiday weather broke down into an "utterly intense" storm.
The 505 weather-related calls LFB took overnight were mainly regarding flooding in the capital. No fires were reported to have started by lightning strikes.
Torrential rain at Kew Gardens saw more than half an inch of rainfall in an hour.
As west London residents recover from the dramatic storms on Saturday night (May 26), forecasters have warned of more storms throughout Sunday (May 27).
A Met Office yellow weather warning of heavy thunderstorms is in place until 6am on Bank Holiday Monday (May 28), covering much of England and all of Wales.
When can you expect storms on Sunday?
In Ealing , thundery showers and light winds are predicted at 1pm, before clearing slightly at 2pm. They're then set to return at 6pm and stick around until 10pm.
Over in Hillingdon , stormy weather is set to begin at 1pm and will stick around until 8pm, according to BBC Weather. It will return for around an hour at 10pm.
Hounslow residents can also expect the bad weather to begin at 1pm and last until 3pm. Thundery showers will begin again at 4pm and will apparently continue for six hours.
'15,000-20,000 lightning strikes'
On Saturday night (May 26), BBC weatherman Tomasz Schafernaker tweeted: "Mother of all #thunderstorms now over London.
"Oh boy! This UTTERLY INSANE. I've never seen a storm with such frequent lightning in my life I don't think. Mostly sheet lightning and not too loud but flashes are spectacular."
Met Office meteorologist Charlie Powell said information suggested there were "somewhere between 15,000 and 20,000 strikes across the UK during the overnight period".
He explained: "Temperatures overnight did not fall much below 15 or 16 degrees, for the end of May that's a pretty hot and humid night so everything was primed.
"We had some storms coming in from northern France and some building up in the Channel and they sort of spread out and have been working their way in.
"It looks like there just one huge area of thundery showers that worked across London just before midnight."