The jumps meetings at Fontwell and Towcester on Sunday are both subject to precautionary inspections on raceday morning.
Fontwell officials will take a look at the track at 8am, while their counterparts at Towcester will check half an hour later.
Fontwell clerk of the course Ed Arkell reports the track to be raceable at present, but even though the covers have been down for a few days, he feels it prudent to check conditions in the morning.
He said: "It's precautionary and due to the risk of frost. We are raceable at the moment and the course has been covered since Tuesday, so we are optimistic, we're just being cautious.
"The forecast is for about minus 1.5C overnight and the covers will cope with that, but you are never quite sure at this time of the year."
Sub-zero temperatures are also expected overnight at Towcester, where clerk of the course Robert Bellamy said: "You've got to be on your guard with the weather as it is, so we've called a precautionary check in case temperatures drop lower than forecast.
"We're forecast around minus 2C, but it's the wind chill that could cause a problem. The feeling is we'll be OK, and we don't race until 2.20."
24 March 2017Bob Baffert wants to rule the World with awesome Arrogate
Charlie Appleby maps out Classic gameplan with exciting filly Wuheida
Coneygree going great guns for Sizing John showdown at Punchestown
Sam Twiston-Davies sides with Saphir Du Rheu in Grand National at Aintree
Jean-Claude Rouget stars Almanzor and La Cressonniere set for big 2017
Cheltenham ace Yorkhill heads Ryanair entries at Fairyhouse
Supreme ruler Labaik in great heart with Fairyhouse and Punchestown on the radar
'Slow process' as Toast Of New York continues to be assessed for racing return
Hopes high Derek Fox will return from injury to ride One For Arthur in National
Mags Mullins in no hurry to map out Debuchet plans
Enda Bolger hoping Aintree fences will fire up On The Fringe
23 March 2017Nigel Hawke continues hot streak at Ludlow
Sweet success for Bonbon at Cork
Let's Dance figures in Fairyhouse list
Cheltenham hero Presenting Percy in frame for Grade One honours at Punchestown
Karl Burke keen on Temple Stakes return for Quiet Reflection
Red-hot Richard Johnson secures Warwick four-timer
Warren Greatrex has Punchestown plan for Haydock winner The Nipper
Ruth Carr issues Kempton poser to new recruit Sovereign Debt
Aintree 'the target' for injured Barry Geraghty
Willie Mullins has strong hand in Topham Chase at Aintree
Kim Bailey happy to play it cool with Charbel after Cheltenham woe
Andrew Slattery looking to new recruit Dinkum Diamond to sparkle at Naas
22 March 2017BHA planning to toughen up licensing procedures for new jockeys
Tully East likely to head to Punchestown following Festival triumph
David Pipe looking to National duo to shine on Aintree stage
Dai Walters hoping to mount Mildmay challenge with Whisper
Arrogate drawn in stall nine for Dubai World Cup assignment
Sandra Hughes hoping Acapella can make Punchestown amends
Vieux Lion Rouge leads Pipe's National assault
Clan Des Obeaux back in the groove at Exeter for Paul Nicholls
Robin Dickin gives Thomas Crapper Topham entry at Aintree
More Of That replaces Minella Rocco as Jonjo O'Neill's Grand National hope
Creggs Pipes blowing hot as Naas stages Flat curtain-raiser
Joseph O'Brien says Edwulf is 'absolutely perfect' and on the way home
Nico de Boinville says Might Bite has the appetite to show 'immense potential'
Fairyhouse-bound Foxrock set to swerve Grand National at Aintree
All roads lead to Aintree for Paul Nicholls' Saphir Du Rheu
21 March 2017Louisa Carberry to break new ground with first British runner at Newbury
Ch'Tibello set to seek Punchestown compensation for Cheltenham disappointment
Colin's Sister to seek Fairyhouse redemption following late Cheltenham absence
Jonjo O'Neill rules Minella Rocco out of Grand National
Jilly Cooper and Bob Champion the star guests at Raceform reunion
Bill Turner hoping late Brocklesby contender will emerge from small team
James Doyle set to continue Australian role with Godolphin
David Pipe could seek Aintree atonement with vanquished Moon Racer
Airlie Beach in contention for Fairyhouse prize
Ellmarie Holden planning chase campaign for Ex Patriot next term
Malcolm Jefferson to target Aintree with Arkle runner-up Cloudy Dream
Harrington sets sights on Punchestown Gold with Cheltenham hero Sizing John
Colin Tizzard biding his time on Finian's Oscar decision
Nicky Mackay set for lengthy spell on sidelines following Chelmsford spill
Colin Tizzard considering Bowl bid with both Cue Card and Native River
Aintree Hurdle option for Yanworth with chasing campaign on the horizon