The rainstorm of 2012-08-15 ~21:00
From Eth0Wiki
On 15 august 2012, around 9 pm, a massive storm flew over the terrain of Eth0:2012_Summer.
There where many casualties, but notably the village Idiopolis² survived it unscathed. 1
Intensity of the storm
As you can see on this graph, the amount of rain that fell was more than twice as what's considered 'heavy'.
Bibliography
[1] * Cooking While Surviving