Manchester United and Manchester City will have to contend with snow and sub-zero temperatures -- as well as each other -- in Sunday's Premier League title showdown at Old Trafford.
Snow is forecast to fall across northwest England in the hours leading up to kick-off and temperatures are set to drop to -1 degree Celsius (30 Fahrenheit).
While the Old Trafford pitch benefits from under-soil heating, there are concerns about icy conditions outside the ground and the 76,000 fans due to attend have been encouraged to arrive early.
The white-hot rivalry between the clubs means the temperature is guaranteed to rise once the teams take to the field for the 175th Manchester derby.
League leaders City are gunning for a record-equalling 14th successive top-flight win and can put a huge 11 points between themselves and second-place United if they prevail.
But United are seeking to set a record of their own by notching up a 41st home match without defeat and City manager Pep Guardiola is wary of his old foe Jose Mourinho's ability to roll with the punches.
"Until now we cannot complain in terms of results and especially the way we have played," said Guardiola, who was the last away manager to win at Old Trafford in September last year.
"When you see in every game the statistics -- not just the way we play -- we are better in terms of potential goals, possession and chances conceded.
"But I think United are fantastic on that. When the statistics are good they win and when they are not good they are able to win 3-1 (against Arsenal) at the Emirates, one of the most difficult stadiums.
"They conceded 33 shots and they won 3-1. Few teams in the world are able to do that. That's why you have to be careful. You can control, you can do many things good, but then they have the talent to do that."
In their last three league wins -- 2-1 successes away to Huddersfield Town and at home to Southampton and West Ham United -- they had to wait until the 83rd minute or later to score the winning goal.
They then lost at Shakhtar Donetsk in the Champions League in mid-week and although it was a nothing game for City and Guardiola selected a weakened team, it brought a record-breaking streak of 20 straight wins to an end.
United have won their last four games and followed up last weekend's clinical 3-1 win at Arsenal by beating CSKA Moscow 2-1 on Tuesday to follow City into the Champions League last 16.
Yet recent history favours City, who have won on four of their last six visits to Old Trafford in the league, including an earth-shattering 6-1 victory in October 2011.
Mourinho, typically, has tried to rile Guardiola, questioning his former Barcelona nemesis's right to wear a yellow ribbon in solidarity with jailed Catalan separatists and accusing City's players of diving.
"They are a good team. They defend well, they react well to the moment they lose the ball," said the United manager.
"They have a good dynamic in attack, they have creative movement. They have amazing players, they have a fantastic coach, they have lots of good things.
"If you ask me one thing that I don't like a lot it's that they lose their balance very easily. You know, a little bit of wind and they fall."
City midfielder David Silva has been passed fit after sitting out the trip to Shakhtar with a knock, but Vincent Kompany is a doubt and City are guaranteed to be without John Stones and Benjamin Mendy.
Paul Pogba is United's major absentee through suspension, which is likely to bring the tigerish Ander Herrera into Mourinho's midfield.