IRELAND EXPERIENCED ITS warmest autumn on record, Met Éireann has confirmed, in line with rising temperatures globally.

In its Weather and Climate Review of the Year 2021, Met Éireann notes that several temperature records were broken in 2021, in particular during the summer heatwaves.

The report states: “Perhaps more notably though is the continuing pattern of milder temperatures, with Ireland seeing provisionally both its warmest September and warmest autumn on record.

“The average temperature in September was 15.28°C, which is 2.3°C above average; the average temperature in autumn was 12.02°C, 1.8°C above average.”

Temperature records were broken at several stations in September including Phoenix Park, which had its warmest September in 122 years. October and November were also mild months with mean temperatures above average across the country.

“As the year comes to an end, it is clear we are also on track for another warm year with temperatures around 0.9°C above average. This will make 2021 the 11th consecutive year with temperatures above Ireland’s average,” the report adds.

Keith Lambkin, Senior Climatologist at Met Éireann, today said these temperature trends in Ireland “are in line with the average temperature rise we are seeing around the world, due to human-caused climate change”.  

“While future temperature projections vary depending on many factors, ‘all’ future projections suggest further warming. This warming, as well as associated defensive actions, is likely to affect everyone in some shape or form.”

Separately, Met Éireann’s Bonnie Diamond confirmed to The Journal that temperatures tonight could challenge the highest temperature recorded on New Year’s Eve in Ireland to date.

Temperatures might not fall any lower than 12°C in places tonight. The current highest NYE temperature on record for Ireland is 11.4°C, from 31 December 2007.

From heatwaves to storms

Met Éireann’s report states that the year “got off to an unsettled and rather wet start as Atlantic low pressure dominated the weather in Ireland, steering Storm Christoph our way in January with further spells of wet weather in February”.

It continues: “March saw generally mixed weather but as high pressure became well established during April, we saw a very dry and cold month thanks to a cool polar air mass that dominated for much of the month.

“Whilst May was a cool and wet month with above average rainfall and below average temperatures, June and July brought a memorable summer with warm, dry and sunny weather nationwide, with above average temperature across all stations and most stations seeing above average sunshine and below average rainfall.  

July in particular was a notable month characterised by widespread heatwaves and long dry spells. A blocking high pressure and tropical continental air mass led to the hot and dry conditions, with Met Éireann issuing its first ever High Temperature warning advising the public to take care in the heat.

“At least 10 weather stations across Ireland reached heatwave conditions, where temperatures of at least 25°C were recorded for at least 5 days in a row. Ireland had its first ‘Tropical Night’ in 20 years at Valentia Observatory in Kerry, where temperatures overnight didn’t fall below 20°C.”

Northern Ireland also set a new record for its highest temperature, with 31.3°C reached in Castlederg, Co Tyrone and Co Armagh on 21 and 22 July.

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Following the heatwave, which ended with some intense and thunderous downpours and flash flooding, the Met Éireann report notes that August was “a month of mild and changeable weather”.  

“The mild theme continued into September, which was provisionally the warmest September on record for Ireland with temperature records broken at several stations including Phoenix Park, which had its warmest September in 122 years. October and November were also mild months with mean temperatures above average across the country.  

“However whilst October was a rather wet month thanks to several Atlantic low pressures, including ex-Hurricane Sam, November was a dry month dominated by high pressure, though Storm Arwen brought wet and windy conditions to northern areas towards the end of November.”

The report adds that December has been “another mild month, most memorable for Storm Barra which brought severe and damaging winds triggering Orange and Red wind warnings for many areas earlier in the month”.

More information on notable Irish weather events in 2021 can be read here.  

With reporting by Emer Moreau