St Patrick’s Day, falling in early meteorological spring, can bring a variety of weather types to Ireland. The location of high and low-pressure systems around Ireland can lead to cold arctic airmasses moving down from the north, or warm tropical airmasses moving up from the south. The strengthening spring sunshine can make it feel quite warm but can also spark off convective shower activity in the afternoon.
Wintry conditions are not uncommon on St Patrick’s Day in Ireland. In 1979 an Arctic airmass brought north-easterly winds with widespread snow showers. Lying snow was recorded in many counties including Dublin, Wicklow, Kilkenny, Cork, Tipperary, Offaly and Louth, where the Drogheda Saint Patrick’s Day parade was cancelled due to heavy snow.
The lowest temperature recorded in Ireland on St Patrick’s Day since 1940 was –8.0 °C at Collooney, Co Sligo in 1989, where a frosty start was followed by a dry and bright day across the country.
Fig 1 – Synoptic chart for 17th March 1989
Warm weather can also feature on St Patrick’s Day in Ireland, such as in 2005. A very mild tropical maritime airmass moved over the country from the south between the 16th and 20th. During this warm period 19.6 °C was recorded at Ashford (Cronykeery), Co Wicklow, which is the highest temperature recorded on St Patrick’s Day since 1940. Only a few days later, on the 19th, Valentia Observatory, Co Kerry recorded its highest ever March temperature of 20.7 °C.
Unusual weather extremes have also been reported on St Patrick’s Day in the past. In 1995 a tornado was reported in County Meath. Ireland lay in a very unstable and cold north-westerly airflow associated with a deep depression to the north of Scotland. This brought heavy wintry showers, with thunderstorms reported at both Mullingar and Shannon Airport before midday. Thunderstorms were widely reported through the afternoon as a showery trough moved across the country. The tornado was reported between 1410 and 1430 UTC, moving quickly eastwards in a strong westerly flow over a path approximately 28km long. It was accompanied by lightning and hailstones of up to 5cm in diameter. The tornado caused considerable structural damage to dwellings and farm buildings and the noise from the approaching tornado was described as “like a roar of a low-flying aircraft”. The full report on this event can be found here.
Fig 2 – Synoptic chart for 17th March 1995
Although there have been no named storms in recent years on St Patrick’s Day, it can often be windy. The highest winds recorded on March 17th since 1940 in Ireland were reported in 1968 at Malin Head, Co Donegal. The highest gust was 154 km/h while highest 10 min mean wind speed was 89 km/h.
The highest rainfall recorded since 1940 on St Patrick’s Day was 80.7 mm, reported at Glenvickee (Caragh River Area), Co Kerry in 1964. On the sunny side, the highest number of sunshine hours was 10.6 hours, reported at Dublin Airport in 1985.
Fig 4 – Synoptic and Airmass chart for 12 UTC on St Patrick’s Day 2024
St Patrick’s day in 2024
Fig 4 – Synoptic and Airmass chart for 12 UTC on St Patrick’s Day 2024
Last St Patrick’s Day, a low-pressure system was situated in the mid-North Atlantic with a central pressure of 973 hPa. This directed a fresh to strong south to south-westerly airflow across the country during the day with embedded weak weather fronts in the flow. The morning and early afternoon were quite cloudy, especially in the Midlands and East.
Sunny spells, initially in the southwest from late morning, spread north-eastwards across the country during the day. There was scattered, mainly light, showers during the morning and early afternoon that become mostly confined to the North and Northeast later in the afternoon and early evening.
During the late evening a band of heavier showers moved into the West of the country. It was relatively mild with afternoon temperatures ranging between 12 and 16 °C. This meant conditions were generally good for the St Patrick’s Day parades across the country.
And… this year?
For your latest St Patricks Day forecast, check our National Forecast (or your relevant Regional forecast) or the latest info on our socials.
Lá Fhéile Pádraig Sona Daoibh, from all of us here at Met Éireann!