Lowest temperature of winter reported at Mullingar

The lowest air minimum temperature of the winter was -8.2 °C reported at both Mullingar, and at Dunsany, County Meath, on Saturday January 9 - both their lowest winter minimums since 2011.

The figures are contained in the Met Éireann Climate Statement For Winter 2020-21, which summarises it as ‘cool and wet overall, mild finish’.

Summary

A weakened and disrupted stratospheric polar vortex in December, January and the first half of February allowed high pressure systems to develop in polar regions, which kept the North Atlantic Jetstream displaced to the south for the majority of winter, leading to cooler than average temperatures in Ireland.

The re-strengthening of the stratospheric polar vortex for the second half of February led to the Jetstream moving north again and milder conditions returning.

Troughs of low pressure repeatedly stalled over Ireland during December, bringing widespread rain or showers for much of the month.

A short dry period around Christmas was followed by Storm Bella on December 26 and 27.

The first third of January saw blocking high pressure keeping it mostly dry and cool with some wintry precipitation in places.

The second third saw a more active Atlantic dominated spell with rain or showers on most days and storm Christoph affecting Ireland between the 18th and 20th.

The final third saw a cold block to the northeast and milder air to the southwest pushing weather fronts in over the country, giving heavy rain in places, and some wintry falls in the north.

The first half of February was cool, with slow moving low pressure for the first week giving way to cold easterlies for the second, with further wintry precipitation in places.

The second half of February was mild, with low pressure to the west sending active weather fronts over Ireland from the south, with some flooding in places. The month finished sunny and settled with high-pressure building from the south.

Rainfall:

Above average everywhere, highest in the South and East

All rainfall totals were above their Long-Term Average (LTA) for the season.

Percentage of seasonal rainfall values ranged from 105% (seasonal rainfall total of 374.8 mm) at Finner, County Donegal to 151% (seasonal rainfall total of 416.0 mm) at Roche’s Point, County Cork.

Seasonal rainfall totals ranged from 243.4mm (129% of its LTA) at Casement Aerodrome, County Dublin to 625.1mm (percentage of LTA 135%) at Valentia Observatory, County Kerry.

The highest daily rainfall total was 41.4mm at Newport, County Mayo on Tuesday January 19.

The number of rain days ranged from 60 days at Oak Park, County Carlow to 82 days at Belmullet, County Mayo.

The number of wet days ranged from 43 days at Dublin Airport to 71 days at Valentia Observatory, County Kerry.

The number of very wet days ranged from six days at Mullingar, to 24 days at both Valentia Observatory, County Kerry and Cork Airport.

It was the wettest winter for the last five years at 10 stations including Phoenix Park, Oak Park, County Carlow, Dublin Airport, Moore Park, County Cork, Sherkin Island, County Cork, Roches Point, County Cork, Dunsany, County Meath, Johnstown Castle, County Wexford, Valentia Observatory, County Kerry and Cork Airport.

Temperature:

Below average nearly everywhere

Nearly all mean air temperatures were below their Long-Term Average (LTA) for the season.

Deviations from mean air temperature for the season ranged from -0.8 °C (4.7 °C mean temperature) at Markree, County Sligo to 0.1 °C (5.3 °C mean temperature) at Phoenix Park.

Mean temperatures for the season ranged from 4.2 °C (at its LTA) at Knock Airport, to 7.3 °C (0.4 °C below its LTA) at Sherkin Island, County Cork (its coldest winter since 2011).

The season’s highest temperature was reported at Phoenix Park on Tuesday Feruary 23 with a temperature of 14.6 °C.

The season’s lowest air minimum was -8.2 °C reported at both Mullingar, and Dunsany, County Meath on Saturday January 9 (both their lowest winter minimum since 2011), while the lowest grass minimum was -12.9 °C reported at Oak Park, County Carlow also on Saturday January 9.

All stations reported air and ground frost during the season.

The number of days with ground frost ranged from 21 days at Malin Head, County Donegal to 56 days at Markree, County Sligo.

The number of days with air frost ranged from five days at Sherkin Island, County Cork to 33 days at Mount Dillon, County Roscommon.

Sunshine:

Above average everywhere, highest in the south

All available sunshine totals were above their Long-Term Average (LTA) for the season. Percentage of seasonal sunshine values ranged from 102% (seasonal sunshine total of 175.8 hours) at Casement Aerodrome, County Dublin, to 133% (the season’s highest seasonal sunshine total of 238.6 hours) at Cork Airport, (its sunniest winter since 2011).

Seasonal sunshine totals were lowest at Malin Head, County Donegal with 147.4 hours (No LTA comparison). The highest number of daily sunshine hours recorded this season was 10.2 hours at Dublin Airport, on Sunday February 28 (its highest daily sunshine for winter on record (record length 79 years).

The number of dull days ranged from two days at Knock Airport, to 43 days at Casement Aerodrome, County Dublin.

Wind:

Gales, strong gales and storm force winds reported

Seasonal mean wind speeds ranged from 6.8 knots (12.6kmh) at Ballyhaise, County Cavan, and Mullingar, to 18.0 knots (33.3kmh) at Malin Head.

Gales were reported on numerous days, with up to strong gales reported on 10 days during the season.

Storm force winds were reported on Sunday February 14 and Friday December 4.

The number of days with gales ranged from zero days at a few stations to 21 days at Malin Head.

The number of days with up to strong gales ranged from zero days at Dublin Airport, to five days at both Mace Head, County Galway and Malin Head.

The season’s highest 10-minute mean wind speed was reported at both Malin Head, and Belmullet on Friday December 4 and Sunday February 14 respectively, with 51 knots (94kmh).

The highest gust was 68 knots (125kmh) reported at Belmullet, on Sunday February 14.

Only one of the three named storms during the season, Storm Bella on December 26, brought strong winds to Ireland.