The bad weather has damaged much of this year's crop here and in Britain.
Malting barley, which is used for brewing and whiskey making, is the top-paying crop for cereal growers and harvesting has just begun.
The crop has also been damaged in Britain and across Europe due to the weather, and there is already a world shortage because of drought elsewhere.
The shortage has caused world prices to double this year, and farmers say supplies in Ireland could be significantly down.
The Irish Farmers Association is warning that even though barley accounts for less than 1% of the price of a pint, the scarcity could result in higher prices for beer and spirits.
Diageo says they are watching the situation very closely, but at this stage they are not unduly concerned.
A Diageo spokesman said malting barley is just one of their input costs, and at this stage it would be premature to speculate about any impact on pricing.
