Freezing temperatures and snow across Britain had jeopardised the start of the iconic four-day meeting, but race organisers were always confident that the frost covers placed over the turf on Monday night would let racing go ahead.
The conditions were the coldest ever seen for the start of the festival: temperatures plummeted to a wind chill factor of -11° on Monday night and fresh snow fell on Tuesday morning.
The start of the racing was pushed back 35 minutes and the Cross Country Handicap Chase was delayed until Thursday.
Clerk of the course Simon Claisse said: "What is unusual is not so much the overnight temperatures but the effect of the wind-chill with daytime temperatures only getting to a couple of degree.
"Normally, when you are planning for a Festival, you might see an overnight frost of minus three or four but you are into a daytime temperature of nine, 10, 11, 12-plus.
"We have never had to lay down frost covers before the Festival before. We made preparations to do so one year but as the weather turned out we did not need to."
