Past changes in the Earth's surface energy balance are recorded in the ground as perturbations of the subsurface thermal regime. Here we reconstruct ground surface temperature histories (GSTH) from temperature versus depth profiles measured at 246 sites distributed across Canada. We show that the ground has warmed about 0.7 K in the last 100 years. Spatial variability is significant and indicates that the largest warming is in the southern areas of Canada. The apparent signal for the Little Ice Age (LIA) does not appear to be homogeneous across Canada.