Many parts of the country had their coldest September in more than two decades.
All parts of the county were colder than normal with temperatures 0.4 degrees below normal on average.
Shannon Airport, Mullingar and Ballyhaise were at at least a degree below normal, making it the coldest September since 1994.
It was a relatively dry month for most places, except for September 11th, which was very wet across the country.
Newport, Co Mayo, experienced 79.4mm (more than three inches) of rain on that day alone - its wettest September day since records began 55 years ago.
Valentia Observatory in Co Kerry recorded 55.4mm, its wettest September day since 1993, and Sherkin Island in Co Cork 60.5mm, the wettest since records began there in 1980.
Wettest September
Mace Head, Co Galway, experienced 161.3mm of rain throughout the month, its wettest September since records began in 2009.
The lowest total was 26.3mm (44 per cent of the long term average) at Casement Aerodrome, Co Dublin reflecting an east-west split.
It looks like the glorious Indian summer we are having will come to an end this weekend.
Temperatures reached a high of 19.1 degrees at Oak Park, Co Kilkenny, on October 1st, exceptionally warm for the time of year. Many places had between 10 and 11 hours of sunshine.
Met Éireann forecaster Pat Clarke said people should make the best of the good weather this weekend as more cloud and rain is forecast for next week.
Rain to creep in
Saturday will see rain creep into the southwest of the country and Sunday will be fresher than of late with strengthening winds.
Monday will see a return to more unsettled, fresher weather . It will be wet and windy on Monday but very mild for the time of year, with temperatures between 15 and 18 degrees.
Tuesday will see rain spread across the country from west to east.
