Saturday's feature event at Newbury has been abandoned and Sunday's Arab meeting at the same venue has also been called off.
The Weatherbys Super Sprint, boasting a prize fund of £135,000, was set to be the highlight of a competitive card but the signs were ominous when the card was called off due to the deluge.
Clerk of the course Richard Osgood said: 'Due to unprecedented rainfall today, leading to parts of the racecourse being flooded, we have had no choice but to abandon.
'The rainfall since 8am has been 80 millimetres and that was on top of the 10 millimetres we had overnight, making a total of 90 millimetres.
'Further heavy showers and rain is possible, so we had no alternative but to abandon.'
Haydock have also abandoned their Saturday evening meeting due to a waterlogged track.
Clerk of the course Kirkland Tellwright called a 7am inspection earlier in the week as conditions at the track were already heavy.
Further overnight rain has now taken its toll and Tellwright confirmed: 'We have abandoned.
'We had 16 millimetres of rain overnight, it is still raining now and there are areas of standing water on the track.'
Meetings at Newmarket, Ripon, Market Rasen and evening meetings at Lingfield and Tipperary are going ahead.
