2018 a year of extremes with temperatures from -7° to 32°

Weather experienced in 2018 saw extremes on a number of fronts, with temperatures, rainfall and sunshine levels all showing large variances throughout the year.

Met Eireann has compiled the statistics in its annual weather summary for 2018, which it released on Friday (January 4).

Rainfall

Rainfall levels saw a a great deal of variance both in time and areas. Two thirds of rainfall totals were lower than average with one third above average; the west and, surprisingly, the south had the highest percentage of rainfall.

Percentage of rainfall long-term averages (LTAs) ranged from 81% at Mullingar and Mace Head to 116% at Roches Point.

January, April and the last two months of 2018 were wetter than normal with the six months from May to October drier than normal, according to the report.

There were widespread droughts from mid-June to mid-July. Soil moisture deficits were very high during this period, particularly in the south-east.

Annual rainfall totals ranged from 648.1mm (86% of LTA) at Casement Aerodrome, Co. Dublin to 1,760.0mm (113% of LTA) at Valentia Observatory, Co. Kerry.

The highest daily rainfall total was 53.2mm at Dunsany, Co. Meath on March 2 during Storm Emma.

Temperatures

An above-average temperature overall was recorded in almost all stations, according to Met Eireann, though only slightly above average in most places.

This was due to February, March, September and October all being colder than average – counteracting the very warm summer – the report details.

The highest yearly mean temperature was 11.2° at Sherkin Island, Co. Cork, while the lowest yearly mean temperature was 8.9° at Knock Airport, Co. Mayo.

The highest daily temperature was 32.0° reported at Shannon Airport on June 28 – a record for a synoptic station.

Meanwhile, the lowest daily temperature was -7.0° reported at Cork Airport on 1st March (during Storm Emma).

Sunshine

Almost all sunshine totals were above their LTAs over the year, according to Met Eireann.

Percentage of annual sunshine values ranged from 89% – some 1,064.1 hours of sunshine in total – in Co. Mayo to 118% – 1,670.9 hours – in Co. Wexford.

Casement Aerodrome had its sunniest year since 1964 with 1,576.8 hours (115% of LTA). The highest number of daily sunshine hours recorded this year was 16.5 hours at Malin Head, Co. Donegal, on June 28 – its highest daily total since 1955.

It was also a very windy year; 2018’s highest gust was reported in Co. Mayo on January 2, with a speed of 156kph.

The year’s highest 10-minute mean wind speed was 115kph in Co. Galway on September 19.

Monthly summary

In a summation of 2018, the national meteorological office noted that the year began unsettled with a mainly westerly airflow for January, with Storm Eleanor bringing strong winds on January 2.

A cold and dry February finished with a polar continental air mass. This brought snow showers with significant accumulations in the east and south.

Image source: Colm Fingleton, Ratheniska, Co. Laois

Storm Emma at the beginning of March gave widespread snow in a cold and changeable month. The unsettled theme continued during April with temperatures near normal.

May started changeable but overall it was a warm dry and sunny month with high pressure dominating.

The settled conditions continued for most of June and July apart from Storm Hector in the middle of June, which brought wet and windy weather briefly.

Heatwave and drought conditions in many places towards the end of June continued into early July in several places, lasting longest in the south and east – playing havoc on growth conditions for farmers.

Changeable weather returned towards the end of July and continued in the north and west for much of August. The south and east stayed predominantly warm and dry.

September and October were cool and dry, according to the report; however, Storm Ali brought the strongest winds of the year on September 19 followed by Storm Bronagh, and Storm Callum on October 12.