Warm, Wet December

Armagh Observatory reports that December was warmer, wetter and slightly sunnier than average.

The mean monthly temperature was 6.7 degrees Celsius (44.0 degrees Fahrenheit), nearly 2 degrees Celsius warmer than the most recent 30-year (1981–2010) average of 4.9 degrees C. This was the warmest December for 25 years, that is, since December 1988. The maximum air temperature was 14.3 degrees C on the 12th, and the minimum was 4.6 degrees C on 24th. The night of the 12/13th was exceptionally mild, with a minimum air temperature of 11.7 degrees C. This was the second warmest December night recorded at Armagh since records of maximum and minimum temperatures began in 1843. There were 20 days with grass frost and none with air frost. Total precipitation for the month was 102.4 mm (a little over 4.0 inches), nearly a third more than the most recent 30-year average December rainfall, making this the wettest December since 2000. The wettest day was the 29th, which saw a total rainfall of 20.2 mm (0.8 inches).

The number of hours of strong sunshine was 44.3, nearly 10% more than the most recent 30-year (1981-2010) average sunshine for December.

Overall, 2013 at Armagh was slightly warmer, wetter and sunnier than average. The mean temperature for the year was 9.85 degrees Celsius, which may be compared with the most recent 30-year (1981–2010) mean annual temperature of 9.71 degrees C. Precipitation, totalling 841.5 mm (33.1 inches), was slightly more than the most recent 30-year average of 813.0 mm (32.0 inches), and the total number of hours of strong sunshine was 1352.5, some eight per cent more than the most recent 30-year annual average of 1247.4 sunshine hours. These unremarkable average results for 2013 mask an exceptionally cold and damp start to the year, one that finished mild, and in between provided a memorably warm and sunny summer and autumn.

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; mebat signarm.ac.uk; URL: climate.arm.ac.uk.

Last Revised: 2014 January 6th