Thermal imagery was collected for 26 hours over a crevassed region within the accumulation zone of the Haupapa/Tasman Glacier, New Zealand. During the night, the imaged snow surfaces associated with crevasses cooled slower than non-crevassed surfaces resulting in temperature differences of several degrees. Night surface temperature varied across the non-crevassed areas to a smaller degree, primarily in relation to slope. The surface temperature difference between crevassed and non-crevassed surfaces is primarily attributed to the reduced sky-view of crevasses so that a large proportion of longwave radiation is not emitted away from the glacier but is received by opposing crevasse walls. Possible additional causes are that crevasses trap warm air which enables greater sensible heat transfer, crevasses have greater conduction of heat from isothermal glacier ice as a result of limited insulating snow, and crevasse walls have greater amounts of liquid water which delays the onset of surface freezing.