Armagh Observatory recorded that this was the coldest May since 1996, with a mean temperature of 9.85 degrees Celsius.
There were several very cold nights, notably the minimum air temperature recorded on the 1st, which was -1.5C.
There were also several very sharp ground frosts, notably the minimum grass temperature of -7.1C recorded on the 1st, and that of -6.9C recorded on both the fourth and 16th, and 15 ground frosts in total. The warmest day was 17.6C on the 22nd. The month was also much wetter than average, with a total precipitation of 93.85mm. This made it the wettest May since 2006.