(CNN) -- It's the race that never stops -- come rain, hail or sleet.
The Kentucky Derby -- America's most prestigious horse race -- is run annually on the first Saturday in May at Churchill Downs' historic dirt track in Louisville, Kentucky, but this weekend's race has been overshadowed by some torrential downpours.
"This will be our 140th Derby and we haven't postponed one yet," Churchill Downs' senior director of communications and media services told Darren Rogers told CNN.
"Lightning or a washout of the track could potentially cause a delay but a postponement would be highly unusual."
Known as "The Greatest Two Minutes in Sports" for its approximate run time, the Derby is the first race in horse racing's coveted Triple Crown, which also includes the Preakness Stakes and the Belmont Stakes.
Churchill Downs has suffered multiple days of heavy rain but even when 2.31 inches of rain fell on Derby day in 1918 the race was run with Exterminator winning.
Despite the poor weather, horses, jockeys and trainers have continued to brave the conditions.
Tapiture trainer Steve Asmussen said after one session: "It felt like the priest's round of gold in [the movie] 'Caddyshack.' Only, thank goodness, we didn't get struck by lightning at the end of it."
The storm got so torrential on Monday that training for the big event, for which there is a $2 million purse, had to be delayed by half an hour.
The weather two years ago was dire on race day -- the second wettest on record as 1.46 inches of rain fell as I'll Have Another seized the victory -- while last year half an inch of rain fell in the six hours prior to Orb riding to victory.
However, wet weather is nothing new to Derby day, the National Weather Service pointing out that 46% of all Derby days have had rain at some point.
California Chrome's trainer Art Sherman had been hoping for a fast track to suit the colt and the weathermen have reassured him that it ought to be just that despite the recent downpours.
The Kentucky Derby, which is also referred to as "The Run for the Roses" due to the garland of 554 red roses draped over the winner, has been known for its varied weather.
It enjoyed a record high temperature of 92 degrees Fahrenheit (33.3 degrees Celsius) for the 1959 running, while two years previously the high then was a mere 47 degrees Fahrenheit (8.3 degrees Celsius), and in 1989 sleet even fell for a time.
Track conditions ahead of the 140th running of the prestigious thoroughbred race had been sloppy because of the storm system that has brought dire weather and tornadoes to central and southern states in the U.S.
The National Weather Service announced early on Wednesday that the nationwide death toll had reached 35, with reports of almost 100 separate destructions that affected approximately 60 million people across the country.