DRIEST JUNE AT ARMAGH FOR SIX YEARS, WARMER
AND SLIGHTLY SUNNIER THAN AVERAGE
Armagh Observatory reports that June 2021 was drier, warmer and slightly sunnier than average. This was the driest June at Armagh for six years, and the warmest and sunniest for three years.
Total precipitation was 42.3 mm (1.67 inches), including 2 trace values (i.e., 42.2 mm if trace values are ignored). This was approximately two-thirds of the average June precipitation at Armagh, that is, 66.4% of the 183-year long-term (1838–2020) June precipitation at Armagh (63.7 mm) and 67.3% of the most recent (1991–2020) 30-year June average (62.9 mm). This was the driest June at Armagh for six years, that is, since June 2015 (29.5 mm). The wettest day was the 13th with 23.0 mm (0.91 inches) of rainfall, followed by the 24th with 10.5 mm.
The morning of the 10th of June was noteworthy for the occurrence of a rare partial eclipse of the Sun, when the Moon passes nearly exactly between the Sun and the Earth. This was the first such solar eclipse visible from Armagh since the exceptionally deep partial eclipse of 20th March 2015. Despite the morning being mostly cloudy across Northern Ireland and in some places with light rain, this year’s eclipse was widely seen and observed by astronomers at Armagh through occasional gaps in the cloud. The next partial solar eclipse visible from the island of Ireland will be on the morning of 25th October 2022.
The mean monthly temperature was approximately 14.8 degrees Celsius (58.6 Fahrenheit), 1.34 C warmer than the 225-year long-term (1796–2020) average June temperature at Armagh (13.43 C) and 0.72 C warmer than the most recent (1991–2020) 30-year June average (14.05 C). This was the warmest June at Armagh for three years, that is, since June 2018 (mean temperature 16.16 C).
The warmest day (highest maximum air temperature) was 23.1 C (73.6 F) on the 10th. This was also the warmest day of the year up to the end of the month. The second-warmest June day this year was 22.9 C on the 1st.
The warmest night (highest minimum temperature over the previous 24 hours) was 15.7 C during the night of the 9th/10th June, preceded by 14.8 C on the 8th/9th. This warmest night was the warmest June night at Armagh for 16 years, that is, since the pair of very warm June nights over the 17th/18th and 18th/19th June 2005 (16.9 C and 16.2 C respectively). This month’s warmest night was also the twelfth-warmest June night at
Armagh since records of daily maximum and minimum temperatures began at the Observatory in August 1843.
The coolest day (lowest maximum air temperature) was a relatively warm 15.4 C on the 14th, followed by 15.6 C on the 25th. The coolest night (lowest minimum air temperature over the previous 24 hours) was 4.5 C on the 22nd, preceded by 5.6 C on the 18th.
There were eight nights with ground frost, that is, with a minimum grass temperature less than or equal to zero Celsius. The two coldest ground frosts were -4.3 C on the 18th and -3.0 C on the 22nd. There were no nights with air frost.
This June, with 152.3 hours of strong sunshine, was slightly duller than the 140-year long term (1881–2020) June average at Armagh (158.7 hours) but slightly sunnier than the most recent (1991–2020) 30-year June average (144.6 hours). The nearly 10% difference in these average quantities at Armagh is due to quite a sharp reduction in the average number of strong sunshine hours for June that began in the early 1980s, with subsequent average values for the month remaining at the slightly lower level.
The sunniest day was the 21st, with 15.0 hours of strong sunshine, followed by the 27th with 12.9 hours. This was the sunniest June day at Armagh for five years, that is, since the 2nd June 2016, which also recorded 15.0 hours of strong sunshine.
These data refer to observations at Armagh Observatory, which has been recording the weather at Armagh since 1795.