Overcast weather is threatening Trangie for its Annual Macquarie Picnics due to be held tomorrow (Saturday 26 July).

Race secretary Emma Flinn predicts a good crowd after 2,500 came to last year's big day of racing activity.

"The track is in top order but rain might wash us out and we can't be worried about it because its badly needed,'' she said.

Picnic racing has attracted bumper crowds across the Western Plains at Nyngan for the Duck Creek Picnics, Cobar and Carinda in the last few weeks.

Trangie's program will see 6 races with the feature race the Macquarie Picnic Cup over 1400 metres.

First held in 1887, the picnic races are well versed in the flexibility needed to stage a successful event.

"We moved the Picnics to a different date and the committee is assessing if we need to change it back to the original date in December because of the amount of picnic races," Emma said.

"It is historic for the town and community backs it."

Eight gallopers will take to Trangie's dirt track for the big race the Macquarie Picnic Cup.

Dubbo's Connie Greig brings in-form I'M Scarlett who has strong form at the distance along with stable mate, mare Blackhall Kitty who has won at Trangie and this race last year.

Norman, a 7 year old gelding from Gunnedah's Gavin Groth is a picnic specialist and also has strong possibilities.

Still, with rain predicted across the west you'll need to keep an ear out for confirmation of the day's racing.

"We will have a track inspection Saturday morning (July 26) to see if the track is suitable to race on," Emma said.