The signature of solar irradiance variations on decadal-to-centennial climate variability is analyzed by means of statistical analysis of long-term instrumental, historical and proxy data sets. Solar variations associated with the Schwabe, Hale, and Gleissberg cycles are detected by their spatial patterns in sea surface temperature and seal level pressure. Different statistical methods of instrumental and proxy data show that the mode related to solar irradiance fluctuations on multidecadal timescales (Gleissberg cycle) is distinct from the Atlantic multidecadal mode associated to ocean circulation changes. From this, one can infer the degree to which solar variability has contributed to long-term temperature variations during the instrumental and pre-instrumental era.