Worked from 2200 Monday to 0600 Tuesday local on Clacton/North Sea sector relieving some very tired ATCOs from the afternoon shift.
Maastricht were accepting traffic by the time we came in to work the night shift however we still restricted the outbounds due to extreme weather avoidance for arrivals causing increased workload for us, TC, Maas Delta and Koksy. Even had aicraft avoiding at FL400. Dover outbounds were regularly entering our airspace and at one point they had three or four Luton and Stansted arrivals orbitting due to weather.
At about 2300 we were advised of a severe band of weather stretching from overhead Paris to Dover. Avoidance reduced in severity approx 0300 when problems due to turbulence increased. It was not a boring night shift.
So that was the 'real' reason - as you were informed. MDIs were I think 1/5 for most directions.