All the main forecasters say warm air from north Africa is set to sweep up across the country during the coming week.
RTE and BBC forecasters say temperatures on Wednesday could reach between 22C and 24C.
Positive Weather Solutions senior forecaster Jonathan Powell said: “People shouldn’t pack away their barbecues just yet as there is a burst of warmth to see out September and bring in October. Ireland will see some decent weather, with pleasant sunshine and temperatures.”
A forecaster for Met Éireann said: “Warm, humid and breezy days are expected from midweek, with a good deal of bright weather and sunny spells, although some rain and drizzle is also likely, mainly in the west and heavy at times.”
Irish Weather Online forecaster Peter O’Donnell said: “A warm spell is likely from Tuesday to the end of next week. Inland parts of the south and east could see hazy sunshine boosting temperatures into the 19C to 24C range.”
Temperatures should rise on Wednesday and continue into the weekend.
Before that Donegal will be hit by some heavy showers on Sunday, say the forecasters.
With dreadful weather predictions for the winter ahead, it might be a good time to enjoy the final blast of heat of the year.
The temperatures could boost further the number of people attending the European Surfing Championships in Bundoran all week with crowds predicted of 25,000.