Violent storm force winds, including the strongest gust of wind ever documented at a Galway coastal station, were recorded in mid-September as Storm Ali passed over the country, according to Met Éireann’s monthly weather report.
Described as a "dry, cool" month, weather conditions took a nasty turn halfway through September with the arrival of storms Ali and Bronagh as well as storm Helene, which passed close to Ireland between September 16th and 20th.
Storm Ali hit the country on September 19th, bringing force 11 winds, with gusts on the west coast reaching 142km/h (79 knots), the highest level recorded since the Mace Head station in Co Galway opened in 2004.
The storm also brought heavy rain to the north and west of the country and was followed by strong winds and more heavy rainfall from Storm Bronagh on September 20th.
Two people were killed and tens of thousands left without power after Storm Ali swept the country in mid-September. Elvira Ferraii from Switzerland died after the caravan she was staying in was blown onto a beach in Co Galway and electrician Matthew Campbell from Belfast died in the Slieve Gullion Forest Park after he was hit by a falling tree while working for the Northern Ireland Water Utility.
Temperatures for September were cooler than usual. The coldest air temperature was reported at Mount Dillon in Co Roscommon on September 29th where it fell to -2.2 degrees. The lowest grass temperature, also at Mount Dillon, was -5.4 degrees on September 24th.
More than half of weather stations reported ground frost during the month, with 10 days of ground frost reported at Mount Dillon. Less than half of weather stations reported air frost.
The warmest day of the month was reported in Phoenix Park in Dublin on September 2nd where the temperature reached 25.1 degrees.
The highest number of sunshine hours was recorded at Johnstown Castle in Co Wexford and the lowest level was at Knock airport in Co Mayo.
Knock airport reported 11 dull weather days compared to just five dull days at Casement Aerodrome in Co Dublin.
The warmer weather returned from September 22nd, with high pressure bringing more settled and sunny conditions in the final week of the month.
Rainfall was below average, with the highest rainfall levels recorded at Newport, Co Mayo, which experienced the wettest day of the month, on September 17th. The lowest rainfall levels for the month were recorded at the Casement Aerodrome in Co Dublin.