Thursday's meeting at Wincanton must pass an 8am precautionary inspection on raceday morning.
Although the Somerset circuit is raceable, course officials are taking no chances.
Overnight temperatures are set to drop to minus 2C, but the inspection has been called in case the frost is sharper than has been forecast.
Clerk of the course Barry Johnson said: "I'm very confident we'll be fine - we'll be OK with minus 2C - but some forecasts are predicting minus 4C.
"There's no frost in the ground now, but the ground is quite wet. It's very much a precautionary inspection."
Leicester's meeting on Thursday is also subject to an 8am precautionary inspection in the morning.
Frost is the main issue at the track, with temperatures set to drop to as low as minus 5C.
A maximum daytime temperature of 2C on Thursday has also been forecast.
Clerk of the course Jimmy Stevenson said on Wednesday morning: "There's no frost whatsoever this morning - we are perfectly raceable - but there is quite a severe frost forecast tonight.
"If we think we have a chance at 8am, we'll probably call another inspection later in the morning and then, possibly, look again. We've got to be patient."
24 April 2014War saunters to easy success
Quevega five-timer still on course
Wylie trio go for Gold
Cyclone blows into Punchestown
Rain set to help Punchestown
Rifles aimed at York
Dante considered for Arod
Carpenter faces stamina question
Tonto strives for Sandown scalp
Telescope sights fixed on Sandown
Prize lined up for Greffulhe raid
Celebration time for super Sire
Taghrooda swerves Sandown heat
Concorde checks in for Punchestown
No Sandown run for Oscar
Un De Sceaux to skip Punchestown
Treve among stellar Ascot entries
Charline still in Guineas mix
Big guns remain in Guineas frame
Prince in Punchestown frame
Sparrow set for Punchestown spin
Balder to take novice test
Connell eager for Tank chase run
23 April 2014Telescope tops Richards runners
No rush for Annie target
Cosgrave appeal set for Monday
Hughes set for Sandown return
France adds flair to Guineas
Mullins drops Vautour Champion hint
Exciting Bunker given Dante date
Culloty keen on Gold run for Heeled
Hannon triple-handed in Guineas
Resurge revived for Epsom return
Sandown option for Battalion
Johnston pair clash in Derby Trial
Reckless Abandon returns to track
22 April 2014Rizeena delights in Guineas workout
Carberry targets swift return
Williamson escapes serious injury
Rizeena thrills Brittain on gallops
Door bags National glory
Twiston-Davies hits four-timer
Joe suffers shock defeat
Scudamore hits century mark
Ivan lands Fairyhouse prize
Thousand shows star quality
Cirrus set for Treve clash
Houblon heads Gold contenders
Guineas still on Berkshire radar
21 April 2014Door bags National glory
Wilson passes away
Ivan lands Fairyhouse prize
Stepper set for trip drop
Richards in Telescope sights
Ladies geared for Summer repeat
Hill out of Irish National
No Dundeel at Royal Ascot
Clowance up for the Cup
Garner hit with lengthy ban
Memories in Final flourish
Fitz powers home at Fairyhouse
Toner hits target for Elliott
Joe ready for Cork outing
Lennon looking to call tune
Ground holds key to Tonto show
Lucky escape for Cook
Mind called up for National service