WET JANUARY, COOLEST FOR ELEVEN YEARS, SUNNIER THAN AVERAGE
Armagh Observatory reports that January 2021 was the wettest at Armagh for three years, the coolest for eleven years, and the sunniest for four years. Total precipitation was 101.2 mm (3.98 inches) including 10 trace values, that is, 100.7mm if trace values are ignored. This is almost 40% more than the average January precipitation at Armagh. The wettest day was the 19th with 22.9 mm of rainfall associated with the passage of Storm Christoph, followed by the 27th with 20.6 mm. The 18th, which preceded Storm Christoph, was the third-wettest day and produced 12.2 mm of rainfall.
Snow fell on three days, namely the 7th, 24th and 31st, with ice pellets on the 26th. There was some snow on the ground for a total of six days, from the 7th to the 9th and the 24th to the 26th. A rainbow was observed on the afternoon of the 21st.
The mean temperature was 3.12 degrees Celsius (37.6 Fahrenheit), which was much cooler than average and the coldest January at Armagh for eleven years. January 2021 was approximately 1.0 C cooler than the 225-year long-term (1796–2020) average January at Armagh (4.17 C) and nearly 1.9 C cooler than the most recent (1991–2020) 30-year average (5.00 C).
The highest maximum air temperature, or warmest day, was 10.7 C on the 13th, followed by 10.0 C on the 28th. The lowest maximum air temperature, or coolest day, was 2.0 C on the 24th followed by 2.8 C on the 7th. The highest minimum air temperature was 6.5 C on both the 14th and 29th, followed by 6.0 C on the 28th. The lowest minimum air temperature was -5.3 C on the 9th, followed by -4.3 C on the 4th. There were 17 nights with minimum air temperatures less than or equal to zero Celsius and 23 nights with ground frost, that is, with minimum grass temperatures less than or equal to 0.0 C. The sharpest of these ground frosts was –15.6 C on the 4th and –15.5 C on the 6th.
With 51.2 hours of strong sunshine January 2021 was nearly 11% sunnier than the longterm (1881–2020) January average at Armagh (46.18 hours) and 8% sunnier than the most recent (1991–2020) 30-year January average (47.41 hours). The sunniest day was the 3rd with 5.5 hours of strong sunshine, followed by the 25th with 5.3 hours.
These data refer to observations at Armagh Observatory, which has been recording the weather at Armagh since 1795.
FOR FURTHER INFORMATION PLEASE CONTACT: Mark Bailey at the Armagh Observatory, College Hill, Armagh, BT61 9DG. Tel.: 028-3752-2928; FAX: 028-3752-7174; email@example.com; URL: http://climate.armagh.ac.uk/.