Nocturnal measurements of air, temperature and longwave radiation were taken in a Eucalyptus delegatensis shelterwood and in a clearfelled control site. On average the shelterwood exhibited temperatures between 1°C and 2°C warmer. Longwave radiation correlated well with percentage sky view as determined from fish eye lens photographs. The shelterwood seems to decrease the radiation loss by an average figure of 21 per cent on a cloudless night. The Brunt cooling theory is used to relate the air temperature and radiation figures.