Thursday's meeting at Wincanton has been abandoned due to a waterlogged track.
Clerk of the course Barry Johnson initially called an inspection for raceday morning after substantial overnight rain.
However, he brought that check forward to 12.30pm following further rain, before eventually calling the meeting off around 12 noon.
Johnson said: "We've had 34mm of rain since one o'clock and it's still raining.
"I have never seen it so wet. There is more rain forecast for Thursday and we have no chance of recovering in time for racing."
Officials at Hereford have also been forced to abandon their National Hunt fixture.
Clerk of the course Keith Ottesen announced a lunchtime inspection earlier this morning following persistent rain, and to make matters worse a culvert (a type of drain) that runs through the centre of the course has burst.
Ottesen said: "It's been getting worse and we're up to 27 millimetres of rain now. We weren't expecting anywhere near that amount."
He added: "Up to 7am we'd had 14mm but as it carried on raining all of the water from the surrounding areas and the water courses are culverted and can't cope with it all.
"We are flooded in parts because those water courses that take the water around the racecourse and underneath it have been breached. The ground everywhere is saturated and cannot take this amount of rain in such a short space of time."
23 July 2016Ryan Moore shines on Highland Reel to claim King George glory at Ascot
Kimberella ghosts home for Dandy Nicholls in York Dash
Librisa Breeze blows hot to earn International honours at Ascot
Time Test fends off Mondialiste to claim York Stakes
Frankel filly Fair Eva dazzles in Princess Margaret Stakes at Ascot
Apex King rules at Ascot on 'emotional' day for Eddery family
Muthmir and Marsha headline King George Stakes entry at Goodwood
Lumiere to bypass Goodwood in favour of Deauville test
Prince Of Lir heads dual British raid on Prix Robert Papin
Emma Lavelle on weather watch ahead of Junction Fourteen Galway goal
Ascot woe for Jamie Spencer as Namhroodah demoted in dramatic Valiant Stakes
Olivier Peslier - Really good chance for Dartmouth in King George
Charlie Appleby has Boynton booked for Vintage Stakes duty
Royal Ascot winner Persuasive unlikely to take Nassau chance
Impressive start for Kazimiera at Ascot
Roger Charlton tests Time in York Stakes
Marco Botti thinks Bahamas can shine in Pat Eddery Stakes at Ascot
Dean Ivory seeking International honours with Librisa Breeze at Ascot
Frankel filly Fair Eva ready to roll at Ascot
22 July 2016Ascot drama as Namhroodah demoted in Valiant Stakes
Leading Stewards' Cup contender Outback Traveller to miss Goodwood
Guy Harwood remembers motoring to the top with Dancing Brave
Big Orange ripe for Goodwood Cup defence
Godolphin give Antiquarium the chance to shine in Goodwood Cup
Royal runner Dartmouth strives for King George glory at Ascot
Aidan O'Brien considers Curragh comeback for US Army Ranger
Derby favourite Churchill digs deep to take Tyros Stakes
Promise To Be True still unbeaten after Silver Flash success
Pyromaniac to miss Galway Hurdle despite quashing of 'schooling' ruling
Frankie Dettori closing in on 3,000th winner
Leading Stewards' Cup contender Golden Steps to swerve Goodwood
Deauville as well as Goodwood an option for Lumiere
Classic stars on Goodwood collision course in Sussex Stakes
Martyn Meade sweet on Irish Rookie in Valiant Stakes at Ascot
Royal runner Dartmouth spearheads King George septet at Ascot
21 July 2016Jonathan Burke just denied on Limerick return
Smart entry for Park Stakes at Doncaster
On Her Toes proves fleet-footed to Star at Sandown
Mile-and-a-half test could see Ventura Storm take Leger chance
Stuart Williams hopes Royal Birth can deliver at Ascot
Marco Botti ponders German raid with Dylan Mouth
Time Test clocks in for York challenge
Ken Condon considers Irish Champion Stakes test for Success Days
Roger Varian makes 'heartbreaking' call to withdraw Postponed from King George
William Knight hoping for Goodwood rain ahead of Jackhammer Vintage date
Dawn delivers Bath glory for Oppenheimer
Toormore tops 14 contenders for Lennox Stakes
Middleham Park Racing swoop for Marco Botti duo Grendisar and Naadirr
Harry Dunlop taking patient approach with Robin Of Navan
O'Brien family field two of six bidding for Silver Flash glory
Churchill set Tyros test at Leopardstown
Urban Fox on the prowl for James Tate in Sandown's Star Stakes
Dermot Weld resists St Leger urge with Harzand
20 July 2016Jonathan Burke 'fit and ready to go' as jockey returns at Limerick
Roger Varian rules Postponed out of King George at Ascot
Karl Burke banks on Quiet Reflection improvement at Haydock
Rose De Pierre team look to the future for 'lovely filly'
Belardo set to swerve Goodwood and head to Deauville
Juddmonte International target for King George favourite Postponed
Our Kylie in tune at Musselburgh to tee-up Galway bid
Francesca Cumani can bring 'new perspective' to racing coverage
Vega in line for bigger things after Curragh success
Upbeat Chris Meehan recovering well from ambulance drama
Richard Gibson rules out Haydock run with Gold-Fun
Bocca Baciata team set their sights on Group One glory
Irish trip ruled out for Prix Foy possible Silverwave