COOL, DRY NOVEMBER WITH ABOUT AVERAGE SUNSHINE. AUTUMN AS A WHOLE SLIGHTLY DULLER AND WARMER THAN AVERAGE

Armagh Observatory, 4th December 2017: Armagh Observatory reports that November 2017 was slightly cooler and drier than average, but with approximately average sunshine.

The mean monthly temperature was approximately 6.6 degrees Celsius (43.9 Fahrenheit), nearly half a degree C warmer than the long-term (1796-2010) average November temperature at Armagh but 0.4 C cooler than most recent (1981-2010) 30-year average.

The warmest day (highest maximum air temperature) was 13.8 C, which occurred on the 21st, and the coldest day (lowest maximum air temperature) was 4.1 C on the 24th. The warmest night (highest minimum air temperature) was 11.0 C on the 21st, and the coldest night (lowest minimum air temperature) was -0.4 C on the 24th. There were 17 ground frosts, the coldest of which was -6.7 C on the 29th, and just two air frosts.

Total precipitation was 63.15 mm (2.49 inches), including three trace values, which is approximately 15% less than the average November precipitation at Armagh. The wettest day was the 21st, with 17.2 mm (0.68 inches) of rainfall.

There were 65.3 hours of strong sunshine during the month. This is close to the long-term (1881-2010) average number of hours of strong November sunshine at Armagh, although approximately 10% more than the most recent (1981-2010) 30-year November average. The sunniest day, with 6.1 hours of strong sunshine, occurred on the 25th.

An aurora was seen on the 6th; and ice pellets, snowflakes and sleet were recorded on the 23rd, and snowflakes again on the 24th. Geese were seen flying west on the 15th.

Taking the three months September, October and November together, the meteorological autumn was slightly warmer than average, with about average rainfall and slightly less than average strong sunshine. The mean autumn temperature was approximately 10.46 C, which is nearly 1.1 C warmer than the long-term (1796-2010) average autumn temperature at Armagh and 0.33 C warmer than the most recent (1981-2010) 30-year average. Total precipitation was 221.95 mm, including 13 trace values, which is slightly more than 97% of the most recent (1981-2010) 30-year average November precipitation at Armagh; and there were 239.8 hours of strong sunshine. Autumn 2017 was nearly 15% duller than the long-term (1881-2010) average at Armagh and nearly 10% duller than the most recent (1981-2010) 30-year average. This was the dullest autumn at Armagh since 2011.

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: http://climate.arm.ac.uk

Last Revised: 2017 December 14th