Crowds close to the anticipated 4,600 came from far and wide today for the highly-anticipated event, said Michael Edwards Dubbo Turf Club chairman.

"We were very anxious with the weather honestly," he said.

"It's impacted with a few people, but the place is chock-a-block.

"It's been a great day and a fantastic crowd considering the circumstances.

"People are having a great time."

For some it was their first or second year, but Di Mellow and her group have been going to Derby Day together for around seven years.

They get to the Dubbo Turf Club early, bring their fold-up chairs and nibbles, sit underneath an umbrella and have a great time.

"It's a great opportunity to dress up, have a little win, a couple of drinks and catch up with friends," Ms Mellor said.

Attendees have been known to spend extreme amounts on the day including outfit, drinks and betting.

But Ms Mellor said she allows only about a $200 total budget for the day.

"I put a couple of dollars on each way and normally come home with what I went in with, so I'm happy with that," she said.

Sally Cullennard has been going to Darby Day with the same group for four years and said she uses the day as a social event and does not spend too much.

"I don't spend an awful lot- I wear what's already in my cupboard," she said.

"I'd have no idea what I would spend.

"I use the day to come out and catch up with people I haven't seen in a while, relax and have a few drinks."

It was a windy day with a light shower or two, which proved to be problematic for some attendees, but Ms Mellor said that is "part and parcel of the day."

"People should be grateful it's not too hot."

Paul Morton attended Derby Day for the second year in a row with a shirt-matching group consisting of him and nine of his mates.

He said his group would collectively spend about $1,000 on bets.

"It's a great day out- we've got tickets to the marquee this year so we're going a little bit fancy," Mr Morton said.

Lincoln and Jess Finn attended the day together for the first time and planned to spend $1,000 each, including outfit, drinks and bets.

"I love the Derby Day fashion," said Ms Finn.

Gavin Copelin has been attending Derby Day on and off for 30 years and this year brought son James along for the first time.

The self proclaimed "horse people" probably know more about gambling than the average attendee.

But the pair only plan on putting $200 on the day's races, Mr Copelin said.

"I'm not a real big gambler- it's just a great day out," he said.