Armagh Observatory has reported that January 2018 was very wet, and slightly cooler and sunnier than average.
This was the seventh wettest January on record at Armagh, and the wettest for two years, that is, since the even wetter January 2016.
Total precipitation was 127.25 mm (5.01 inches), including three trace values. This is nearly 75% more than the long-term (1796-2010) average January precipitation at Armagh and 71% more than the most recent (1980-2010) 30-year average January precipitation at Armagh.
The wettest day was the 16th with 14.3 mm of rainfall, followed by the 3rd and 23rd, each with 12.4 mm.
Snow was recorded falling on five days, and at least some snow was reported lying on the ground on six days.
The greatest snow depth was approximately 5 cm on the 17th.
The mean temperature was approximately 4.5 degrees Celsius (40.1 degrees Fahrenheit), cooler by 0.2 C than the most recent (1981-2010) 30-year average January temperature at Armagh, and 0.4 C warmer than the long-term (1796-2010) average.
The warmest day (that is, the highest maximum air temperature) was 12.6 C on the 27th, followed by 12.2 C on the 28th.
The coldest day (lowest maximum air temperature) was 2.3 C on the 16th.
The warmest night (highest minimum air temperature) was 6.9 C on the 28th, and the coldest night (lowest minimum air temperature) was -4.8 C on the 7th.
This night also had the sharpest ground frost of the month, namely -11.1 C.
It was followed on the 8th by another very cold night registering a minimum air temperature of -4.6 C and a minimum grass temperature of -10.9 C.
In all, there were 20 nights with ground frost and six with air frost.
January 2018 was also slightly sunnier than average.
There were 51.1 hours of strong sunshine, nearly 3% more than the long-term (1881-2010) average at Armagh and 10% more than the most recent (1981-2010) 30-year average.
These data refer to observations at Armagh Observatory, which has been recording the weather at Armagh since 1795.