We describe results from nearly a decade of tilt measurements produced by two arrays of shallow borehole tilmeters: one in a semiarid environment at Pi¿on Flat Observatory (PFO), California (depth of burial 4.5 m) and the other in a maritime-Arctic environment at Adak, Alaska (depth of burial 2 m). Although renovation and reinstallation of the instruments at the two sites reduced thermal noise, it did not change the secular records significantly. This implies that the large tilts observed reflect instability of the ground rather than the sensor, so that deeper installations should give better results. The PFO data show large rainfall-related tilts (caused by near-surface weathering) and also periodic temperature-related tilts (from several thermoelastic effects). The Adak data are dominated by tilts from the annual temperature cycle (though by a small amount than at PFO), but at other frequencies they show essentially the same power levels as at PFO. Both data sets confirm earlier results that burial at such shallow depths, even in apparently stable material, is inadequate for the measurement of tectonic tilts. ¿ American Geophysical Union 1988