Two long mean air temperature series are presented for Armagh Observatory; one based on twice daily `spot' temperature readings, 1796-1882, and the other on daily maximum and minimum temperatures, 1844-1992. Our data comfirm the correlation of temperature with solar cycle length, first suggested by Friis-Christensen and Lassen (1991) and, for this site, extends their result a further 65 years, back to the end of the 18th century.