Officials at Ludlow and Wincanton have called precautionary inspections for 8am on Thursday ahead of their afternoon meetings.
Ludlow experienced a hard frost on Tuesday night and with a cold day forecast followed by a further frost tonight, they feel it best to check conditions in the morning.
The going is reported to be heavy, soft in places on the hurdles track, with frost covers employed on the chase course fences.
Temperatures at Wincanton are reported to have dropped to minus 7C overnight, leaving parts of the track frozen.
While a further frost is expected, landings and take-offs at the track have been covered and temperatures are expected to rise on Thursday