Climate Statement for November and Autumn 2020

NOVEMBER 2020

Mild, wet in the West, drier in the East
November 2020 was a mild, Atlantic dominated month, with a wind flow mostly between southerly and westerly. The very active weather from the end of October continued for the first few days of November, with deep Atlantic low-pressure systems bringing active weather fronts across the country from the west. High pressure developed from the south for the second half of the first week, keeping it mostly dry for several days. A trough of low-pressure moved up from the south at the end of the first week, pushing the high pressure away. For the following two weeks, low pressure to the north dominated once again bringing bands of rain and showers from the west on most days, up to the 24th. Active weather fronts brought wide-spread and sometimes heavy rain across the country on the 8th, 10th, 11th and 24th, with the western half of the country receiving the bulk of the rain. High pressure dominated for the final week of the month, which kept the active weather fronts away from Ireland. There was a lot of dry weather with slack winds but it become cooler with frost and fog more of a feature. Some weak weather fronts traversed the country at times, which brought cloudy, murky conditions.

Rainfall: Above average in most places, highest in the West and Northwest 

The majority of monthly rainfall totals were above their Long-Term Average (LTA). Percentage of monthly rainfall values ranged from 66% (the month’s lowest monthly rainfall total of 48.1 mm) at Dublin Airport to 138% (monthly rainfall total of 168.8 mm) at Claremorris, Co Mayo. Monthly rainfall totals were as much as 206.6 mm (121% of its LTA) at Newport, Co Mayo.

Temperature: Above average everywhere

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 0.4 °C (7.7 °C, 9.9 °C mean temperature) at Markree, Co Sligo and Sherkin Island, Co Cork respectively to 1.5 °C (8.7 °C mean temperature) at Phoenix Park, Co Dublin.

Sunshine: Above average in the South and East

Nearly all available sunshine totals were above their Long-Term Average (LTA). Percentage of monthly sunshine values ranged from 87% (monthly sunshine total of 51.8 hours) at Shannon Airport, Co Clare to 112% (monthly sunshine total of 73.0 hours) at Casement Aerodrome, Co Dublin.

Wind: Strong gales reported

Monthly mean wind speeds ranged from 6.4 knots (11.9 km/h) at Moore Park, Co Cork to 16.4 knots (30.4 km/h) at Mace Head, Co Galway. Gales were reported on 9 days during the month, with strong gales reported on Monday 2nd and Friday 18th. The number of days with gales ranged from zero days at a few stations to 7 days at Mace Head, Co Galway. The number of days with up to strong gales ranged from zero at most stations to 2 days at Mace Head, Co Galway. The month’s highest gust was reported at Belmullet, Co Mayo on Sunday 1st with 58 knots (107 km/h). The month’s highest 10-minute mean wind speed was 44 knots (82 km/h) at Mace Head, Co Galway on both Monday 2nd and Friday 18th.

Full report <<here>>

AUTUMN 2020

Sunny. Wet in the West and Northwest, drier in the South and East

The first two thirds of September where warm with high pressure to the south of Ireland dominating and pushing the Jetstream further north. It was wet in the Northwest but relatively dry elsewhere. The final third of the month was cool as the Jetstream moved south again and Atlantic low-pressure systems brought widespread rain. October was a cool, wet and windy month with Ireland situated under, or on the cooler northern side of the Jetstream for much of the time. Low pressure dominated the first week, followed by a relatively dry period with high-pressure close by. A very strong Jetstream brought stormy conditions for the final third of the month with Storm Aiden (the first named storm of the 2020/2021 storm season) affecting Ireland on the 31st. November was a mild month overall as the Jetstream moved north again. Low pressure to the north and high pressure to the south for most of the month resulted in a predominately west or southwesterly airflow. The western half of the country saw a lot of rain off the Atlantic while the East stayed drier. The month finished drier everywhere under slack high-pressure conditions with fog and frost in places.

Rainfall: Highest in the West and Northwest

The majority of seasonal rainfall totals across the country were below their Long-Term Average (LTA). Percentage of seasonal rainfall values ranged from 84% (seasonal rainfall total of 242.6 mm) at Roche’s Point, Co Cork to 127% (seasonal rainfall total of 450.8 mm) at Claremorris, Co Mayo. Seasonal rainfall totals ranged from 188.4 mm (87% of its LTA) at Casement Aerodrome, Co Dublin to 588.0 mm (123% of its LTA) at Newport, Co Mayo.

Temperature: Above average in most places

The majority of mean air temperatures were above their Long-Term Average (LTA) for the season. Deviations from mean air temperature ranged from -0.1 °C (9.9 °C , 11.1 °C, 11.4 °C, 10.3 °C mean temperature) at Markree, Co Sligo, Shannon Airport, Co Clare, Mace Head, Co Galway and Athenry, Co Galway re-spectively to 0.7 °C (10.9 °C mean temperature) at Phoenix Park, Co Dublin.

Sunshine: Above average everywhere

All available sunshine totals were above their Long-Term Average (LTA) for the season. Percentage of seasonal sunshine values ranged from 110% (seasonal sunshine total of 321.2 hours) at Casement Aerodrome, Co Dublin to 118% (seasonal sunshine total of 347.8 hours) at Cork Airport. Co Cork.

Wind: Gales, strong gales and storm force winds reported and one named storm

Seasonal mean wind speeds ranged from 6.1 knots (11.3 km/h) at Moore Park, Co Cork to 16.1 knots (29.8 km/h) at Mace Head, Co Galway. Gales were re-ported on numerous days with up to strong gales reported on 8 days during the season. Storm force winds were reported on the 31st Oct during Storm Aiden.

Full report <<here>>