Freezing temperatures and heavy snow have forced the postponement of this week's English League Cup semi-final first leg matches.
The tie between Blackburn Rovers and Aston Villa, scheduled for last night, and today's Manchester derby between City and United were called off because of dangerous travelling conditions across the north of England.
"The decision was taken in conjunction with the police match commander on the grounds of public safety," said a statement on Rovers website.
"It is snowing heavily in Blackburn, as it has been all morning, and advice locally is not to travel unless it is absolutely necessary."
United said on their website that the first leg at City's Eastlands ground had been re-arranged for January 19 with the second leg now scheduled for January 27.
The decision means the Premier League games between Man. United and Hull and Man. City and Stoke, due to be played at Old Trafford and the Britannia Stadium on January 26 and January 27 have now also been postponed.
City and United, who train close to each other at Carrington, were forced to cancel their sessions yesterday and tell their players not to report for duty. Indeed, advice for the general public has been to stay indoors, with City closing their Eastlands ticket office due to the atrocious conditions.
As with Blackburn, the problem at Eastlands is not anything to do with the pitch. The surrounding roads are in a mess and motorways are also at a standstill in certain areas.
Under normal circumstances, the games would have been re-arranged for next week on the same days.
However, with Manchester City's Premier League encounter with Blackburn Rovers due to be broadcast live on Monday evening, that was ruled out.
Meanwhile, no new dates have yet been announced for the Rovers vs Villa match.
Stephen Davenport, senior meteorologist at MeteoGroup, said: "This is stretching the limits of short to medium-term forecasting but so entrenched is this weather pattern that it seems only a major upheaval in the atmosphere will bring a return to something milder.
"Should conditions continue in a similar vein then by March we might just be looking back at one of the coldest winters of the last 100 years."