Temperatures reached a balmy 21C in some parts of the county earlier.
And there were very heavy showers between the sunshine.
At one stage a massive downpour in Letterkenny caused flooding on many roads with the Pearse Road badly hit.
There were also heavy showers in Gaoth Dobhair, across Inishowen and Fanad as well as Ballybofey and around Glenties.
Of course the high temperatures and heavy showers will be a mere blip compared to the horrible weather we can expect in the next 48 hours as Hurricane Katia bears down on Donegal with 80mph winds and torrential rain.
Here’s the latest from irishweatheronline:
SUNDAY … Breezy, becoming windy later in the afternoon, intervals of cloud and sunshine, rather warm in south where highs 17-19 C, more overcast in north with highs 14-17 C. Winds south to southwest 15-30 mph at first, rising later to 30-50 mph.
SUNDAY NIGHT … Stormy with blustery southwest winds developing, heavy or squally showers with thunder and hail mixed with a few clear breaks, winds rising to SSW 40-60 mph in many areas and 50-80 mph in coastal west and northwest. Strongest winds towards daybreak, overnight temperatures steady near 15 C north to 17 C south.
MONDAY … Windy or very windy, with storm force wind gusts west and later north, to near hurricane force in exposed locations of northwest coast (SW veering WSW 50-80 mph), while further south in most of Leinster and Munster, gale force winds at times, showers clearing away east with some sunny intervals, winds WSW 35-55 mph … temperatures in the north around 15-17 C but rising to near 20 C in southeast during the morning before levelling off near 17 C later.
Some risk of wind damage and coastal flooding around high tides or during very strong winds mainly in north Clare, coastal Galway, Mayo, Sligo and Donegal, as well as wind damage in higher parts of Connacht exposed to west.