Officials at Ayr have been forced to abandon this afternoon's jumps meeting at the Scottish track.
Clerk of the course Anthea Morshead said: "The frost didn't come in until after midnight. But it's still continuing to drop and between 6 a.m. and 7 a.m. it's gone from minus four to minus five.
"The Met Office are saying that the air temperature won't rise until after 11 a.m. and the ground temperature not until after lunchtime.
"So unfortunately it's given us no choice. It's depressing because it looked a really good card."