Weather of June 2017
The north Atlantic Jet Stream prevailed for the first two weeks of the month. This steered successive frontal systemseastwards over Ireland, bringing rain and showers on most days. The period from 7th to 10th was very unsettled as a deep mid Atlantic depression tracked between Ireland and Iceland before filling. The Azores High then gradually extended a ridge towards Ireland around the middle of the month. This resulted in a fine, warm and mainly dry third week with good sunshine, though it was cloudier in the far northwest. It became unsettled again for the final week as low pressure returned, bringing lengthy spells of rain and it was notably dull on the final days.
Rainfall: Most stations had above average monthly totals:
The majority of monthly rainfall totals across the country were above their Long-Term Average (LTA) for the month. Percentage of monthly rainfall values ranged from 87% (the month’s lowest monthly rainfall total of 63.0mm) at Finner, Co Donegal to 172% (monthly rainfall total of 124.8 mm) at Johnstown Castle, Co Wexford. Monthly rainfall totals were as much as 141.5 mm (percentage of LTA 148%) at Valentia Observatory, Co Kerry. The highest daily rainfall was 31.1 mm, recorded at Valentia Observatory, Co Kerry on the 9th. The number of wet days1 ranged from 12 at Carlow (Oak Park) to 21 at both Newport, Co Mayo and Valentia Observatory, Co Kerry. The number of very wet days3 ranged from zero days at Finner, Co Donegal to six at Valentia Observatory, Co Kerry.
Temperature: Highest daily maximum in over 56 years at Phoenix Park:
All mean air temperatures across the country were above their Long-Term Average (LTA) for the month. Deviations from mean air temperature for the month ranged from at longterm average (13.8°C mean temperature) at Athenry, Co Galway to 1.7°C (15.2°C the month’s highest mean temperature at Dublin (Phoenix Park.)) Mean temperatures for the month were lowest at Knock Airport, Co Mayo with 12.8°C (difference from LTA 0.5°C.) The month’s lowest temperatures were recorded on 26th June with the lowest air minimum reported at Mullingar, Co Westmeath with a temperature of 3.6°C and the lowest grass minimum reported at Mount Dillon, Co Roscommon with -0.6°C. The month’s highest maximum was reported on 21st June at Dublin (Phoenix Park) with a temperature of 28.6°C (its highest June temperature since 1961.) There was only one day with ground frost and that was at Mount Dillon, Co Roscommon on the 26th. There was no air frost reported this month.