Climate Statement for Spring and May 2023

Spring 2023 (March, April & May)

Mild overall, wet start, dry finish

Spring 2023 began with a very wet month and finished very dry. March was wet and dull overall after a dry and cool beginning. Low pressure to the southwest of Ireland dominated after the first week. Storm Larisa, named by Météo-France, brought heavy rain and snow at the beginning of the second week. The rest of the month was milder with numerous bands of frontal rain or showers crossing the country in a relatively mild cyclonic airflow. April was mild overall. The month fluctuated between Scandinavian high pressure dominance, bringing some dry periods and Atlantic low pressure dominance, bringing some wet periods. A deep depression, named storm Noa by Météo-France, gave widespread wet and windy weather towards mid-month. A period of easterly winds followed with high pressure to the north. The month finished showery with some heavy and thundery downpours. May was warm and calm overall. During the first half of the month, low pressure brought bands of frontal rain and heavy thundery showers in places. The second half of the month was very dry everywhere and dominated by blocking high pressure. This led to drought conditions in the East.

Rainfall: Above average nearly everywhere, wet March, average April, dry May

Nearly all rainfall totals were above their 1981-2010 Long-Term Average (LTA) for the season. Percentage of seasonal rainfall values ranged from 76% (seasonal rainfall total of 194.8 mm) at Finner, Co Donegal to 142% (seasonal rainfall total of 342.8 mm) at Athenry, Co Galway. Seasonal rainfall totals ranged from 176.1 mm (98% of its LTA) at Oak Park, Co Carlow to 374.4 mm (119% of its LTA) at Valentia Observatory, Co Kerry. The highest daily rainfall total was 34.7 mm at Cork Airport on Thursday 9th March. The number of rain days ranged from 50 days at Dublin Airport, Co Dublin to 59 days at a few stations. The number of wet days* ranged from 37 days at Oak Park, Co Carlow to 49 days at both Newport, Co Mayo and Knock Airport, Co Mayo. The number of very wet days* ranged from 1 day at Finner, Co Donegal to 15 days at Valentia Observatory, Co Kerry. Phoenix Park, Co Dublin had its wettest spring since 1998 with 225.6 mm (134 % of its LTA) and Dublin Airport had its wettest spring since 2002 with 232.6 mm (140 % of its LTA). By the end of May, there were five on-going dry spells* lasting between 17 and 20 days and four on-going absolute droughts* lasting 17 days, all in the East of the country (see May climate statement for more details).

Provisional monthly gridded 2023 rainfall (%) for Ireland on a monthly basis.

Provisional monthly gridded 2023 rainfall (%) for Ireland on a monthly basis.

Temperature: Above average everywhere, warmest in the Southwest

All mean air temperatures across the country were above their LTA for the season. Deviations from mean air temperature for the season ranged from 0.4 °C (9.1 °C mean temperature) at Markree, Co Sligo to 1.5 °C (10.1 °C mean temperature) at Phoenix Park, Co Dublin (its warmest spring since 2011). Mean temperatures for the season ranged from 8.9 °C (1.2 °C above its LTA) at Knock Airport, Co Mayo to 10.5 °C (0.8, 0.9 °C above their LTA) at both Shannon Airport, Co Clare and Valentia Observatory, Co Kerry (Valentia’s warmest spring since 1997). The season’s highest temperature was reported at Shannon Airport, Co Clare on Tuesday 30th May with a temperature of 24.9 °C. The season’s lowest air minimum was recorded on Monday 27th March at Dublin Airport, Co Dublin with -4.3 °C while the lowest grass minimum was -11.2 °C reported at Markree, Co Sligo on Wednesday 8th March. All stations reported ground frost during the season. The number of days with ground frost ranged from 4 days at Sherkin Island, Co Cork to 44 days at Mount Dillon, Co Roscommon. More than half of stations reported air frost. The number of days with air frost ranged from zero days at Mace Head, Co Galway to 13 days at both Markree, Co Sligo and Mount Dillon, Co Roscom-mon. Four stations had their warmest spring on record. These were Oak Park, Co Carlow with 10.0 °C (1.2 °C above its LTA) (record length 16 years), Moore Park, Co Cork with 10.1 °C (1.2 °C above its LTA) (length 31 years), Athenry, Co Galway with 9.7 °C (0.7 °C above its LTA) (length 13 years) and Casement Aerodrome, Co Dublin with 9.6 °C (1.1 °C above its LTA) (length 59 years).

Dublin Airport, Co Dublin Temperature: Daily mean departure from LTA for Spring 2023 based on 09-09hr Max/Min values

Dublin Airport, Co Dublin Temperature: Daily mean departure from LTA for Spring 2023 based on 09-09hr Max/Min values

Valentia Observatory, Co Kerry Temperature: Daily mean departure from LTA for Spring 2023 based on 09-09hr Max/Min values

Valentia Observatory, Co Kerry Temperature: Daily mean departure from LTA for Spring 2023 based on 09-09hr Max/Min values

Sunshine: Near average, sunniest in the Northwest

Percentage of LTA sunshine values varied across the country. Percentage of seasonal sunshine values ranged from 99% (seasonal sunshine total of 432.1 hours) at Shannon Airport, Co Clare to 102% (seasonal sunshine total of 450.4 hours) at Casement Aerodrome, Co Dublin. Seasonal sunshine totals ranged from 367.6 hours (No LTA comparison*) at Cork Airport, Co Cork to 454.5 hours (No LTA comparison*) at Belmullet, Co Mayo. The highest number of daily sunshine hours recorded this season was 16.0 hours at Malin Head, Co Donegal on Tuesday 30th May. The number of dull days* ranged from 14 days at Malin Head, Co Donegal to 24 days at Cork Airport, Co Cork.

Wind: Gales reported in all three months. Storm force winds reported during storm Noa

Seasonal mean wind speeds ranged from 5.6 knots (10.4 km/h) at Ballyhaise, Co Cavan to 12.7 knots (23.5 km/h) at Mace Head, Co Galway. Gales were reported on 11 days during the season, 7 in March, 2 in April and 2 in May. Strong gales and storm force winds were reported on 1 day during the season. The number of days with gales ranged from zero days at a few stations to five 5 days at Mace Head, Co Galway and Malin Head, Co Donegal. Strong gales and storm force winds were reported on Wednesday 12th April during storm Noa at Sherkin Island, Co Cork. Both the season’s highest gust and 10-minute mean wind speed was reported at Sherkin Island, Co Cork on Wednesday 12th April. The highest gust was 66 knots (122 km/h) while the season’s highest 10-minute mean wind speed was 48 knots (89 km/h).

Sherkin Island, Co Cork: Wind Roses for Spring 2023

Sherkin Island, Co Cork: Wind Roses for Spring 2023

The full report is available here (choose Spring on drop down menu for month) or the PDF is available here

Spring 2023 extreme values at synoptic stations

Spring 2023 extreme values at synoptic stations

*This report is based on available preliminary data from 25 principal weather stations operated by Met Éireann. Synoptic station data is midnight to midnight UTC. Long-Term Averages (LTAs) and “average” refer to the period 1981-2010. A wet day is a day with 1.0 mm or more of rainfall. A dull day is a day with less than 0.5 hours of sunshine. A very wet day is a day with 10.0 mm or more of rainfall. An absolute drought is a period of 15 or more consecutive days to none of which is credited 0.2 mm or more of precipitation. A partial drought is a period of at least 29 consecutive days, the mean daily rainfall of which does not exceed 0.2 mm. A dry spell is a period of 15 or more consecutive days to none of which is credited 1.0 mm or more of precipitation (i.e. daily tot < 1.0 mm). A heatwave occurs where there are 5 consecutive days or more with maximum temperature over 25°C (that is, a daily maximum screen air temperature > 25° C). Sunshine data is from the Autosol Network. LTAs for these sites are currently not used for comparison purposes. For more information, contact Met Éireann at 01-8064200 or e-mail: enq@met.ie

May 2023

Warm, dry and calm. Sunny finish

May was warm and dry overall with high pressure dominating for most of the month, especially the second half. Winds were predominantly westerly to north-westerly, but became easterly towards the end of the month as high pressure moved to the north of Ireland. The month began mostly dry under high pressure, although weak weather fronts kept it cloudy at times. Towards the middle of the first week, Atlantic low pressure systems encroached from the west. This brought widespread frontal rain across the country on the 4th and 7th interspersed with a few days of scattered, sometimes thundery, showers. An unstable air mass brought some active thunderstorm activity to the east on the 8th. Between the 9th and 11th a slack area of low pressure moved from west to east to the north of the country, bringing further scattered bands of rain or showers, sometimes thundery. Towards the end of the second week, pressure rose from the south as the Azores High pushed up over the country and dominated for the rest of the month. Some weak weather fronts pushed through the high pressure at times giving some scattered outbreaks of rain, particularly on the 14th and 20th, but amounts stayed low, especially in the South and East. High pressure intensified over Ireland during the final week of the month, centred just to the north by the end of the month. This brought very dry conditions along with increasing amounts of sunshine.

Rainfall: Below average everywhere, especially in the East with on-going dry periods

All monthly rainfall totals across the country were below their 1981-2010 Long-Term Average (LTA). Percentage of monthly rainfall values ranged from 37% (monthly rainfall total of 30.6 mm) at Mace Head, Co Galway to 87% (monthly rainfall total of 56.7 mm) at Shannon Airport, Co Clare. Monthly rainfall totals ranged from 23.3 mm (39% of its LTA) at Oak Park, Co Carlow to 63.5 mm (84% of its LTA) at Athenry, Co Galway. The highest daily rainfall total was 21.4 mm at Valentia Observatory, Co Kerry on Sunday 7th. The number of rain days ranged from 8 days at Phoenix Park, Co Dublin to 15 days at a few stations. The number of wet days ranged from 5 days at Oak Park, Co Carlow to 11 days at a few stations. The number of very wet days ranged from zero days at Phoenix Park, Co Dublin to 2 days at a few stations. By the end of May, there were five on-going dry spells and four on-going absolute droughts in the East of the country. The dry spells were at Phoenix Park, Dublin Airport, Casement Aerodrome, Co Dublin, Oak Park, Co Carlow (20 days) and Johnstown Castle, Co Wexford (17 days). The absolute droughts were at Phoenix Park, Dublin Airport, Co Dublin, Oak Park, Co Carlow and Johnstown Castle, Co Wexford (17 days).

Rainfall % of 1981 - 2010 Monthly Average for May 2023 (Provisional)

Rainfall % of 1981 – 2010 Monthly Average for May 2023 (Provisional)

 

Total Monthly Rainfall (mm) for May 2023 (Provisional)

Total Monthly Rainfall (mm) for May 2023 (Provisional)

Temperature: Above average everywhere, warmest May at seven stations

All mean air temperatures across the country were above their LTA for the month. Deviations from mean air temperature ranged from 1.0 °C (11.8 °C , 11.9 °C mean temperatures) at Dublin Airport, Co Dublin and Markree, Co Sligo respectively to 2.1 °C (12.9 °C, 13.1 °C, 13.2 °C mean temperatures) at Phoenix Park, Co Dublin, Oak Park, Co Carlow and Moore Park, Co Cork respectively. Mean temperatures for the month ranged from 11.7 °C (1.4 °C above its LTA) at Malin Head, Co Donegal to 13.5 °C (1.5 °C above its LTA) at Shannon Airport, Co Clare. The month’s highest temperature was reported at Shannon Airport, Co Clare on Tuesday 30th with a temperature of 24.9 °C. The month’s lowest air and grass minimum temperatures were recorded at Mount Dillon, Co Roscommon with the lowest air temperature reported on Monday 29th with 1.5 °C while the lowest grass minimum was -3.2 °C reported on Tuesday 16th May. There was zero air frosts reported this month. More than half of stations reported ground frost. The number of days with ground frost ranged from zero days at a few stations to 12 days at Mount Dillon, Co Roscommon. Seven stations reported their warmest May on record. These were Phoenix Park, Co Dublin with a mean temperature of 12.9 °C (joint warmest with May 2022, record length 123 years), Oak Park, Co Carlow with 13.1 °C (length 16 years), Moore Park, Co Cork with 13.2 °C (length 55 years), Roches Point, Co Cork with 12.9 °C (1.5 °C above its LTA) (length 17 years), Dunsany, Co Meath with 12.2 °C (1.7 °C above its LTA) (length 30 years), Athenry, Co Galway with 12.6 °C (1.3 °C above its LTA) (length 13 years) and Cork Airport, Co Cork with 12.8 °C (2.0 °C above its LTA) (length 61 years). Most other stations had their warmest May since 2008.

Oak Park, Co Carlow temperature: Daily mean departure from LTA for May 2023

Oak Park, Co Carlow temperature: Daily mean departure from LTA for May 2023

Athenry, Co Galway temperature: Daily mean departure from LTA for May 2023

Athenry, Co Galway temperature: Daily mean departure from LTA for May 2023

Sunshine: Sunniest in the Southeast

Percentage of LTA sunshine values were above average in most places across the country. Percentage of monthly sunshine values ranged from 115% (monthly sunshine total of 214.6 hours) at Casement Aerodrome, Co Dublin to 116% (monthly sunshine total of 210.1 hours) at Shannon Airport, Co Clare. Monthly sunshine totals ranged from 170.1 hours (no LTA comparison*) at Malin Head, Co Donegal to 226.3 hours (no LTA comparison*) at Johnstown Castle, Co Wexford. The highest number of daily sunshine hours recorded this month was 16.0 hours at Malin Head, Co Donegal on Tuesday 30th. The number of dull days ranged from 1 day at both Gurteen, Co Tipperary and Casement Aerodrome, Co Dublin to 4 days at both Malin Head, Co Donegal and Valentia Observatory, Co Kerry.

May 2023 hours of Bright Sunshine observed at each station for each day of the month, grouped by province relative to the highest number of hours possible by end of month (shaded box)

May 2023 hours of Bright Sunshine observed at each station for each day of the month, grouped by province relative to the highest number of hours possible by end of month (shaded box)

Wind: Gales reported at one station, calm overall

Monthly mean wind speeds ranged from 4.7 knots (8.7 km/h) at Ballyhaise, Co Cavan to 10.7 knots (19.8 km/h) at both Mace Head, Co Galway and Malin Head, Co Donegal. Gales were reported at Malin Head, Co Donegal on Thursday 4th and Friday 5th. The number of days with gale force winds ranged from zero day at most stations to 2 days at Malin Head, Co Donegal. There were no strong gales or storms reported this month. Both the month’s highest gust and 10-minute mean wind speed was reported at Malin Head, Co Donegal on Friday 5th. The highest gust was 40 knots (74 km/h) while the month’s highest 10-minute mean wind speed was 35 knots (64 km/h). Nine stations had their lowest mean wind for May on record.

The full report is available here

May 2023 extreme values at synoptic stations

May 2023 extreme values at synoptic stations

Recent Mays in Ireland:

  • 2016: The majority Long-Term Average (LTA) rainfall values were below. All stations had on, or above LTA mean air temperatures and monthly sunshine totals.
  • 2017: The majority of rainfall totals were below their LTA, all mean air temperatures and most sunshine totals were above. No significantly strong winds were reported.
  • 2018: Nearly all rainfall totals were below. All monthly mean temperatures and sunshine totals were above average, and the winds were strongest in the West.
  • 2019: Nearly all rainfall totals were below while mean air temperatures and sunshine totals varied. No significantly strong winds were reported.
  • 2020: All rainfall totals were below average. Mean air temperatures and sunshine totals across the country were above. Post-tropical storm Arthur brought Gales and strong gales.
  • 2021: All rainfall totals were above average. All mean air temperatures were below, while all sunshine totals were above. Strong gales were reported on a number of days.
  • 2022: Rainfall totals varied while all air temperatures were above their LTA. All sunshine totals were below and no significantly strong winds were reported.