Prime Minister Gordon Brown said: "Our thoughts are with all those who have been impacted by these floods, and our thanks go out to all the emergency services and all other agencies involved in the response who continue in their extraordinary efforts to help the people affected."
A statement from the RAF at 2am on Friday described the conditions in Cockermouth as "atrocious".
"The situation has continued to deteriorate over the past two hours with people being forced to break through the rooftops of houses as they frantically seek escape from rising floodwaters," it said.
The rain has been causing problems in Scotland too
The Met Office - which records and measures the weather - said 17.3cm of rain fell on the village of Seathwaite in Cumbria in just 24 hours.
There are currently four severe flood warnings in Cumbria, and 22 flood warnings in the Midlands, Wales and north-east and north-west England and 42 less serious flood watches.
There are nine flood warnings in place in Scotland.