December 2021 Climate in Armagh – Astronotes


Armagh Observatory reviews that December 2021 was wetter, hotter, and duller than common.  The month was outstanding for an unseasonably very heat interval starting close to the top of the month and lasting by way of the New 12 months.  This was additionally the wettest December at Armagh for six years, and the dullest for 3 years, that’s, because the exceptionally uninteresting December 2018.

Calendar 12 months 2021 was outstanding in a number of respects, together with an exceptionally heat spell in July contributing to an equal third-warmest summer season at Armagh (16.2 C), the warmest September on report (15.5 C), the warmest autumn on report (11.9 C), and the second-warmest 12 months (10.5 C) since data started at Armagh round 1795.

The imply day by day temperature for the month was 6.7 C (44.1 F), roughly 2.1 C hotter than the 225-year long-term (1796-2020) December common at Armagh (4.6 C) and practically 1.5 C hotter than the latest (1991-2020) 30-year common (5.2 C).

December 2021 was outstanding for a spell of very heat climate across the finish of the month.  In accordance with the UK Meteorological Workplace, this was brought on by low stress to the west of Eire drawing a stream of heat Atlantic air from the south-west over a lot of the nation.  Normally, however not at all times, the very best temperature every day happens within the afternoon, however on this event the stream of heat Atlantic air led to a sequence of most temperatures occurring at evening.

Right here, the primary excessive most air temperature was 12.6 C, which was noticed to happen near 09:00 GMT across the time of the climate readings on the morning of the twenty ninth.  As this was the very best temperature recorded through the earlier 24-hour interval the worth was attributed to the twenty eighth.

The day by day most temperatures then elevated additional, from 13.2 C through the early hours of the thirtieth (and so attributed to the twenty ninth) to 13.4 C within the early hours of the thirty first (and so attributed to the thirtieth), earlier than reaching a report 14.5 C through the early morning of New 12 months’s Day and so attributed to New 12 months’s Eve (thirty first December).  Subsequent maxima had been 13.3 C on the afternoon of New 12 months’s Day (and due to this fact attributed to 1st January 2022) adopted by 11.0 C throughout early afternoon of the 2nd.

Following the established meteorological conference the 5 warmest New 12 months’s Eves at Armagh at the moment are 2021 (14.5 C), 1850 (12.6 C), 1920 (12.2C), 2011 (12.1 C), and 1916 and 1936 (each 11.8 C).  Equally, the 5 warmest New 12 months’s Days (1st January) at Armagh at the moment are 2015 (13.5 C), 2022 (13.3 C), 1851 (13.1 C), 1991 (12.7 C), and 1860 and 1922 (each 12.6 C).

The bottom most temperature this month was 5.4 C, which occurred throughout early morning of the twentieth and was due to this fact attributed to the nineteenth, adopted by 5.8 C, noticed near 09:00 on the morning of the seventh and due to this fact attributed to the sixth.

The best minimal day by day air temperature this December was 10.6 C, noticed on the night of the thirtieth and due to this fact attributed to the thirty first, adopted by 9.2 C on the night of the twenty ninth and so attributed to the thirtieth. The bottom minimal air temperature was 0.9 C on the fifth, adopted by 1.1 C on each the 2nd and seventh.  There have been solely 14 floor frosts this month, that’s, nights when the minimal grass temperature was lower than or equal to zero Celsius, the bottom two of which had been minus 5.2 C on the fifth and minus 3.9 C on the sixth, and no air frosts.

Whole precipitation this December was 110.85 mm (4.36 inches) together with 3 hint values, that’s, 110.7 mm if hint values are ignored.  This was roughly 41.7% greater than the 183-year long-term (1838-2020) common December precipitation at Armagh (78.2 mm) and 36.2% greater than the latest (1991-2020) 30-year December common.  This was the wettest December at Armagh for six years, that’s, since 186.1 mm was recorded in December 2015.

The wettest day was the twenty fifth with 24.5 mm (0.96 inches) of rainfall, adopted by 18.1 mm on the sixth and 15.1 mm on the seventh.  The latter two measurements had been related to the passage of the damaging Storm Barra.  This 12 months’s Christmas Day was very moist, the third-wettest Christmas Day on report at Armagh and solely barely drier than Christmas Day 2015 (25.0 mm).  With a median temperature of seven.5 C Christmas Day 2021 was barely hotter than the imply December air temperature at Armagh.

Gulls had been seen on a number of days, the Thirteenth, 14th, seventeenth, twentieth and twenty second, with a very giant quantity on the seventeenth circling repeatedly and shifting slowly in a north-easterly path.  A lot of gulls had been additionally noticed flying in a north-easterly path round noon on the twentieth.  The frequency with which gulls have been seen this 12 months over Armagh suggests {that a} colony of gulls could have grow to be established close to town.

Rainbows had been seen on the 4th and sixth, with double rainbows on the 4th and tenth.  Hail was noticed on the 4th, sixth, and seventh, with sleet and snow on the sixth although no snow cowl.  Wind from Storm Barra reached gale power on the morning of the seventh, inflicting tree injury and injury to the Observatory’s sunshine tower.

The month was a lot duller than common, with a complete of solely 27.8 hours of sturdy sunshine, this being 73% of the 140-year long-term (1881-2020) common variety of hours of sturdy sunshine (38.0 hours) and practically 65% of the latest (1991-2020) 30-year common (43.1 hours).

Calendar 12 months 2021 was a record-breaking 12 months although with roughly common sunshine and precipitation.  It was the warmest 12 months at Armagh for 14 years and the second-warmest calendar 12 months since day by day temperature data started on the Observatory round 1795.

The annual imply air temperature was virtually 10.5 C (50.9 F), roughly 1.38 C hotter than the 225-year long-term (1796-2020) common annual temperature at Armagh (9.10 C) and 0.55 C greater than the latest (1991-2020) 30-year common (9.94 C).  The 5 warmest calendar years at Armagh at the moment are 2007 (10.62 C), 2021 (10.48 C), 2006 (10.45 C), 1949 (10.42 C), and 2017 (10.38 C).

Whole precipitation for the 12 months was 799.65 mm together with 57 hint values, or 796.8 mm if hint values are ignored.  That is roughly 98% of the 183-year long-term (1838-2020) common annual precipitation at Armagh (816.15 mm) and 96.8% of the latest (1991-2020) 30-year common (825.3 mm).

Due to this fact, regardless of some very dry and a few very moist months, rainfall – as so typically occurs – averaged out over the 12 months.  Certainly, there may be little or no proof for precipitation both systematically growing or lowering in the long run at Armagh.  Equally, the whole variety of hours of sturdy sunshine at Armagh throughout calendar 12 months 2021 (1284.1 hours) was very near the 140-year (1881-2020) long-term common of 1285.2 hours and the latest (1991-2020) 30-year common (1281.0 hours).

January 2021 was the good at Armagh for 11 years, and wetter and sunnier than common.  February was hotter than common, however wetter than common and with about common sunshine.  Mixed with a comparatively cool December 2020, which was barely sunnier and wetter than common, the meteorological winter 2020/2021 was cooler than common, wetter than common and with about common sunshine.

March 2021 was hotter than common, drier and far duller than common, the dullest March at Armagh for 8 years.  April was a lot colder than common and cooler than March.  This occurs on common solely as soon as each 14 years within the 225-year long-term Armagh report.  April 2021 was additionally exceptionally dry and far sunnier than common, the third-sunniest April on report at Armagh.

Might 2021 was very cool, the coldest Might at Armagh for six years, although this was compensated by a heat late Might financial institution vacation.  The month was additionally very moist, the wettest Might at Armagh for 18 years, resulting in the comment that it typically felt as if April showers had come a month late. The month was sunnier than common, and this led to meteorological spring at Armagh being sunnier than common, although cooler and with about common rainfall.

June 2021 was hotter than common.  This month was exceptionally dry, the driest June at Armagh for six years, and barely sunnier than common.

July was a lot hotter than common, the warmest July at Armagh for eight years.  Most noteworthy was the distinctive 10-day lengthy heatwave extending from the sixteenth to the twenty fifth, throughout which every day achieved a most temperature better than or equal to 26.0 C.  A report most temperature of 31.3 C was recorded on the twenty second, equalling the Met Workplace’s Northern Eire report of 31.3 C noticed at Castlederg the earlier afternoon.  The 5 hottest days noticed at Armagh at the moment are 2021 July 22 (31.3 C), 2021 July 21 (30.5 C), 2018 June 27 (30.4 C), 1934 July 10 (30.3 C) and 2018 June 28 (30.2 C).  July was additionally very dry, the driest July at Armagh for 21 years and the Thirteenth-driest July on report.  The month was additionally sunnier than common.

This record-breaking month was adopted by a hotter than common August that was barely wetter than common and the dullest August at Armagh for 13 years.  The thirty first recorded one of many highest August pressures on report at Armagh, a price (decreased to imply sea degree) of roughly 1035 hPa.

Taking the three summer season months collectively, the meteorological summer season was the equal third-warmest summer season at Armagh since day by day temperature data started round 1795.  The 5 warmest summers at Armagh at the moment are 1995 (16.5 C), 2006 (16.3 C), and 1983, 2021, 2018, 1826 and 2013 (all 16.2C).  The meteorological summer season was additionally a lot drier than common at Armagh, the driest for 8 years, and barely duller than common.

September 2021 was additionally distinctive.  This was the warmest September on report at Armagh (15.5 C), a outcome that included the third-warmest September day at Armagh with a most temperature of 26.2 C on the seventh. September was additionally wetter than common and far duller, the dullest September for 38 years and the seventh-dullest September on report at Armagh.

October was the warmest at Armagh for 15 years, sunnier than common and with about common rainfall.  It was an unusually calm month with no named autumn storms.

These two months had been adopted by an exceptionally heat November, memorable for grass rising all through the month and for leaves remaining on some bushes proper as much as the top of the month.  November 2021 was additionally very dry, the driest November at Armagh for 32 years, and duller than common.

Taking the three autumn months collectively, this was the warmest autumn on report at Armagh, and drier and duller than common.  December 2021 continued the nice and cozy pattern, being hotter, wetter, and duller than common.

Miscellaneous climate notes throughout 2021 included a report of silent lightning on March twenty sixth and a uncommon, spoked rainbow seen from Clogher on the night of the July twelfth.  Through the 12 months, a variety of birdlife has been reported, together with gulls, swallows, swifts, ravens, rooks and crows, buzzards, and kestrels, in addition to a jay and fieldfares.

The annual-averaged developments of temperature, rainfall and robust sunshine recorded at Armagh are proven within the hooked up Figures.  These present respectively the imply annual temperature from 1796 to 2021, the whole annual precipitation from 1838 to 2021, and the whole annual variety of hours of sturdy sunshine from 1881 to 2021.

Imply Annual Temperature

Whole Annual Rainfall

Whole Annual Sunshine

Such figures disguise important month-to-month variability however illustrate the attribute year-to-year variability of the climate at Armagh. Outstanding options embody multi-decadal oscillations and a normal rise of imply annual temperature with time, the latter contrasting with an almost fixed common degree of complete annual precipitation, and a latest improve in sturdy sunshine reversing a earlier downward pattern.

These knowledge check with observations at Armagh Observatory, which has been recording the climate at Armagh since 1795.

For additional data, please contact:

Professor Mark E. Bailey

Emeritus Director of Armagh Observatory

Armagh Observatory and Planetarium

School Hill


BT61 9DG

Tel: 028-3752-2928

E-mail: [email protected]

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