Forecasts suggest about 25 per cent of potential shooting will be available – up from a near 50-year low of one to two per cent in 2005.
"Last year was a complete wipe-out and though it's an improvement, it will still be a poor year," said Moorland Association spokeswoman Amanda Anderson.
Because August 12 falls on a Saturday this year, the starts of many shoots are likely to be delayed until the following week.
"Most people will not be shooting on the 12th," said Adrian Thornton-Berry, a sporting agent who organises several grouse shoots.
"For some that's the way it always has been, and there are a lot of people about on Saturdays."
Great care is taken by gamekeepers and land owners to produce the right environment for a red grouse population to flourish and provide a shootable surplus. But often, nature intervenes.
Mrs Anderson said: "If they get pounded by rain just after hatching, the nests can get washed out and the chicks drown. If the mother is weak and not brooding them well they can get wet and die of pneumonia.
"If it's windy, the chicks get blown away, so they cry and that's like a beacon to a fox. It's very precarious."
West Yorkshire firefighters are still tackling one of the worst fires in decades on Ilkley Moor – a shooting area where at least 500 acres from Addingham to Ilkley have been destroyed.
Mrs Anderson said: "Summer has been lovely, hot and dry, but the consequences are an increased risk of moorland fires, whether they are started deliberately or not.
"If you have had a fire there's little chance of shooting. If it burns into the peat it will burn down and can then pop up anywhere. It takes decades for the land to recover."
Some shoots are cancelled because grouse stocks are considered perilously low.
Shooting will take place across the region including Wensleydale, Swaledale, Nidderdale, Wharfedale, and the North York Moors.