Big meetings under threat
Clerks of the course at the two feature meetings on Saturday are expecting a "challenging" few days because of the weather.
While Ascot and Haydock were raceable on Tuesday, temperatures are set to drop dramatically in the run up to the weekend.
Frost plus the prospect of some snow could threaten both Ascot, where Sprinter Sacre would be the headline act in the Victor Chandler Chase, and Haydock, where the Peter Marsh Chase is the centrepiece.
Ascot reports no problems so far with the going described as soft, good to soft in places.
"Weather conditions haven't been as severe as forecast, but temperatures are forecast to be colder tonight, tomorrow and overnight on Wednesday," said clerk of the course Chris Stickels.
"There is obviously a threat and the forecast does look a little bit challenging.
"We have had frost covers down since last Saturday.
"We are well prepared in anticipation of this coming."
Haydock, where the going is heavy, has also taken the necessary precautions.
"We are covered up. It's been so far so good and we were fit to race (on Tuesday morning) after it got down to minus 2C," said clerk of the course Kirkland Tellwright.
"The next couple of nights look like a bigger test as we might get down to minus 8C or minus 9C.
"Covered or not, that will be a fair challenge.
"All we can do is take it one step at a time."
In the meantime, the cold snap is hitting the race programme.
Officials at Newbury will stage a precautionary inspection at 9am ahead of the track's scheduled meeting on Wednesday.
The frost covers are down at the Berkshire circuit.
Clerk of the course Richard Osgood is confident racing will go ahead, but feels it is sensible to check on conditions.
"We have the entire racing surface covered at the moment and I don't think there will be any problems at this stage, but temperatures are due to get down to minus 3C or minus 4C," he said.
Wednesday's jumps meeting at Newcastle has been abandoned due to being covered by two inches of snow and a harsh frost expected overnight.
Officials at Market Rasen were also left with no option but to abandon Thursday's National Hunt fixture due to snow on the track.
Michael Prosser, regional head of racing for the east for Jockey Club Racecourses, said: "We've got two inches of snow on the ground and the forecast tells us temperatures could get down to minus 4C or minus 5C tonight.
"It is due to be even colder, so I'm afraid there is no possibility of racing."
Ludlow's jumps meeting on Thursday is under threat from frost, with an inspection called for 8am on Wednesday.
Although the course was raceable on Tuesday, with the going described as soft, temperatures are set to dip ahead of the fixture.
"We've got frost forecast tonight and the temperatures we are forecast are for it stay below freezing effectively," said clerk of the course Bob Davies.
"If the forecast is right we will struggle."
Looking further ahead, Cheltenham have deployed frost covers on the chase and hurdles courses for Festival Trials Day on Saturday week.
Head of racing Simon Claisse said: "The current forecast is for temperatures to remain cold for the remainder of this week, with some very hard frosts.
"In view of this, we have put down frost covers on the chase and hurdle courses in order to give Festival Trials Day every chance of going ahead."