Sunniest April for 94 years, Slightly wetter and cooler than average

Armagh Observatory reports that April 2015 was the sunniest April for 94 years, that is since April 1921, and the fourth sunniest since records of strong sunshine began at Armagh in 1881. Despite this, total precipitation was slightly higher than average, and the mean monthly temperature lightly less than the average for the last 30 years.

A total of 204.3 hours of strong sunshine was recorded during April at Armagh, approximately 30% more than the long-term (1881–2010) average April sunshine at Armagh, and more than 43% more than the most recent 30-year (1981–2010) April average. This April produced slightly more hours of strong sunshine than the almost equally sunny April 2007 (203.6 hours), and has become the sunniest April since 1921 (209 hours of strong sunshine) and the fourth sunniest April at Armagh since sunshine records began at the Observatory in 1881. The sunniest day was the 21st, with 13.7 hours of strong sunshine, followed by the 18th with 13.6 hours.

Total rainfall amounted to 61.95 mm (2.44 inches), including 7 trace values, which is approximately 7% more than the most recent 30-year (1981–2010) average April precipitation at Armagh. Although there were no days when snow lay on the ground for any appreciable time, there were two days with hail (the 26th and 27th), one with sleet (27th), and three with light snow (26th, 27th and 28th). A double rainbow was seen on the evening of the 29th. The wettest day was the 11th, with 11.7 mm (nearly half an inch) of rainfall.

The mean monthly temperature, namely 8.2 degrees Celsius (nearly 47 degrees Fahrenheit), was approximately 0.34 degrees C warmer than the long-term (1796–2010) mean April temperature at Armagh (nearly 7.9 C) but 0.29 degrees C cooler than the most recent (1981–2010) mean April temperature at Armagh (nearly 8.5 C). The warmest day (highest maximum air temperature) was 19.7 C on the 23rd, and the coldest night occurred on both the 27th and 28th, with equal lowest minimum air temperatures of -3.2 C.

Among 23 nights that showed a nighttime ground frost (minimum grass temperature less than or equal to zero C) there were four very sharp ground frosts registering minimum grass temperatures of -6.0 C or less. There were four nighttime air frosts.

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: 2015 May 7th