Why it happened
Renewed rain over parts of the country already swamped by weeks of wet weather has led to fresh flooding across the North.
Rain falling on sodden ground means there is nowhere for the excess water to go, which has led to rivers bursting their banks.
To add to the problem, groundwater levels are now so high in some parts of the country that flooding is likely to persist for weeks or even months.
There is also an increased risk of groundwater flooding, which is where water seeps up through earth which is so saturated it cannot hold any more.
The worst-affected areas are across the north-west and north-east of England, where renewed showers – following weeks of heavy rain – led officials to issue hundreds of Boxing Day flood warnings.
Fifteen of these were severe – meaning that there is a danger to life – and were issued by the Environment Agency (EA) across the North East and North West.
As rain continued to land on sodden ground the result was inevitable.
More water poured off hillsides into already swollen rivers, leading to flood defences being breached.
As a result the Calder, Ribble, Wyre and Wenning rivers burst their banks.
Pendle Water, Pimlico Brook, the Burrow and Hellifield Beck were also at risk of breaching, the EA warned.
The Met Office also issued two red alerts for rain, indicating a potential threat to life, in the Lancashire area plus Yorkshire and the Humber.
Forecasters warned that up to 4.7in (120mm) of rain was likely to have fallen in some areas already hit by wave after wave of winter squalls in recent weeks.
That compares with the average rainfall for the whole of December in the North West of 5.7in (145mm). Over high ground between 1.7in (50mm) and 3.1in (80mm) of rain is likely to have fallen yesterday, while some exposed areas in southern parts of Cumbria were likely to be receiving up to 4.7in (120mm).
A yellow warning of rain was issued for parts of North Wales, northern England and southern Scotland.
Most scientists agree that the increasing amount of rain in northern and westerly parts of the British Isles is likely to be one of the symptoms of climate change.
As global temperatures rise and the air becomes warmer, more moisture evaporates from land and water into the atmosphere.
That generally means we can expect more rain and snow and more heavy downpours.
But this extra precipitation is not spread evenly around the globe, and some places might have less rain than before, as climate change causes shifts in the air and ocean currents which can alter weather patterns.
Scientists and forecasters are wary of blaming specific localised weather patterns on wider climate change.
But Government ministers – including Rory Stewart, the floods minister yesterday – have begun to indicate they feel it is to be blamed for recent severe flooding.