Friday's meeting at Chepstow has been abandoned due to a frozen track, while officials at Catterick have called a precautionary inspection for 8am on raceday.
Although Chepstow's track has been covered since Sunday, the current cold spell has still managed to take its toll.
Clerk of the course Keith Ottesen called a 1.30pm inspection to check conditions, but he was left with little choice but to abandon and said: "Unfortunately we are frozen in places underneath the covers. The take-offs, landings, worn areas and shaded areas are severely affected despite the covers."
He added: "We have looked at every forecast and it gives us no prospect of sufficient improvement to be raceable. The covers are generally successful if used for one night of frost and in combination with high daytime temperatures, but the temperature range and the duration of frost combined with dry conditions has seen the frost penetrate the ground."
The prognosis is better at Catterick, where officials found the track to be raceable on Thursday, despite having been frozen in places after an overnight frost.
With another frost expected tonight, officials feel it prudent to call a precautionary inspection in the morning.
"We are currently raceable. The frost from Wednesday night has come out," said clerk of the course Fiona Needham.
"The forecast for tonight is rather grim, but they have been wrong on the whole so far this week, so let's hope they are again.
"It just really depends on what happens overnight - we've been forecast somewhere around minus 4C and minus 5C. We have had cloud cover today and if we retain that then it won't freeze so hard."
