A fortnight ago record November temperatures hit 20 degrees but this weekend values will plummet to zero, bringing more snow.
Met Éireann forecasts wintry showers in Ulster and north Connacht on Saturday night, with a chance of snow and sleet in the north of the country.
Forecaster David Rogers said a cold snap is due to begin around the country on Friday and carry on into Sunday night.
"There will be wintry showers coming down from the north during that period to places like Donegal, particularly over higher ground. Donegal will catch some wintry precipitation with a mixture of rain, sleet and snow which might leave a covering over some of the highest peaks."
The temperatures this weekend will feel particularly cold following an exceptionally mild November, said Mr Rogers, adding that values over the weekend would only fall slightly below average.
“Although it will feel colder there probably won’t be anything in the way of frost because the wind will remain persistent and we’re close the ocean. The ocean is very warm this time of year.”
The colder weather will continue over the weekend with temperatures falling to zero overnight. But milder conditions are expected to return next Tuesday and Wednesday.