Officials at Leicester will hold an inspection at 8am in the morning ahead of Wednesday's fixture.
Clerk of the course Jimmy Stevenson said: "It could be a tricky morning, the forecast doesn't look brilliant with a severe frost.
"We had a minus 2C last night and could probably have got away with it by waiting a bit, but tonight could be a different story."
Wednesday's meeting at Hexham is also subject to a raceday inspection at 8am due to the threat of frost.
Clerk of the course James Armstrong said: "We dropped to minus 1C last night and it's just about raceable now, we had little flurry of snow earlier.
"The forecast for tonight is that little bit colder, around minus 2C, and daytime temperatures might struggle to get above 3C at best, so we need to keep a close eye on it and keep everyone in the picture."
18 June 2013
Stevens is king of the CastleO'Neill ace proves too sharp
Ballydoyle in command in Coventry
Dawn delivers in thriller
Sole powers to sprint glory
Al Thani snaps up Sandiva
O'Brien sounds War cry
Minute's silence remembers Cecil
Duntle on Cambridge duty
Alive and Just in Ribblesdale mix
Passage heads Gold field
Deegan considers Soprano options
Toro out for Palace glory
Cecil's words not lost on Ponsonby
Dawn out for Palace redemption
Hawkwood supplemented for Hardwicke
Flotilla To Drop Back In Trip
Cecil's Chigun in Cambridge action
Al Kazeem and Camelot clash again
De Kock hoping to make history
War ready for Royal Ascot battle
Kingdom set to reign over Ascot
17 June 2013
Magician set for Palace showdownCat clings on for Carroll
Three more winners for Lady Cecil
Monaghan delivers on Midnight
Treve in stunning Diane win
Sapphire target for Trees
Beckett mulls Secret options
Nicholls has broken wrist
16 June 2013
Songbird aiming to fly highMovie has Newmarket on radar
Fahey juveniles primed for action
Stubbs leads O'Brien Coventry team
Salsify on summer break
Kempton target for Benbulben
Top trio head Palace runners
Shea Shea shoots for Stand glory
Animal heads Queen Anne field
Saint-Cloud aim for Dunaden
Magician to be declared for Palace
Soul all heart in York sprint
Kingsgate rules Musselburgh
Sam too sharp for rivals
Hughes makes it pay with Knight
Balding on mark with double
Morawij in a hurry in Scurry
Bartley is queen for a day
Big guns to clash in Coronation
15 June 2013
Marengo set for battle royalSaddler's ready to rock - Oxx
Soprano primed to hit right notes
Balding receives OBE
Victory on a plate for Montaser
Magician run in the balance
Secret set to make Ascot stand
Probert return delayed
Nagle covers Maarek options
Ribblesdale chance for Lark
Walker hoping Guns will fire
Estimate in Royal Gold run