Soaring temperatures have led to a 12% increase in the sales of ice cream over the past 12 weeks.
The latest research from Kantar Worldpanel shows the number of people buying barbeque food is up by 10%.
Alcoholic drinks have also experienced a surge in demand with sales of cider up 14%.
The survey shows that Tesco is Ireland's most popular supermarket ahead of SuperValu and Dunnes Stores.
David Berry, director at Kantar Worldpanel, said: "Tesco remains the leader of the pack among the retailers, increasing its market share to 22.4% – a jump of 0.3 percentage points.
"Over the past 12 weeks, 1.3 million customers chose to shop at Tesco – the highest reach of all the retailers.
"Although the grocer has not notably increased this shopper base compared to this time last year, Tesco has encouraged customers to add an extra item to their baskets every time they shop – upping their average spend by 80c to €25.50.”
SuperValu is second with 21.8% of Irish shoppers buying their groceries there, a rise of 0.1%.
Dunnes Stores also increased its market share by 0.1% after the retailer recorded sales growth of 2.6%.
Kantar said the grocer’s success has come from encouraging customers to up the value of their shopping to an average of €42.60 – an increase of more than €2.50 compared to this time last year.
Meanwhile, Lidl's market share of 11.7% is its highest since October 2017 and Aldi is close behind with a market share of 11.4% after they increased their sales by 2.4%.
The German retailers are doing particularly well in Munster.