Wholesale rates per megawatt-hour decreased from €181.84 in June 2022 to €117.11 this month, according to Wind Energy Ireland's monthly report.
According to the data, Irish wind farms generated one-third of the island's electricity during the first six months of the year, but only 20% in June because of the dry period.
On June 24, wind farms met more than half of Ireland's daily electricity needs.
Wholesale costs decreased even further to €106.98 on windiest days, but they increased to €134.97 when fossil fuels were primarily needed.
The energy sector has recently seen a significant decline in wholesale prices, but consumers have not yet seen these savings on their bills.
Wind Energy Ireland chief executive Noel Cunniffe said: “New wind farms, along with solar and battery projects, will be connecting before the end of 2023 but we really need to accelerate the delivery of onshore and offshore renewables if we are to reach our legally-binding carbon emissions reduction targets.”