Effect of aspect and cloudiness on grass and soil temperatures at a hill site in Raglan County

Abstract Grass and soil temperatures were recorded under pasture in clear and cloudy conditions on north and south‐facing slopes in January, April, July, and October. The north aspect was warmer than the south at all times of the year, because of clear‐weather differences in January and October and also higher cloudy‐weather temperatures in April and July. In clear weather, the north aspect was warmer but the south aspect was colder than in cloudy conditions, particularly in April and July. The mean of daily grass minimum plus maximum gave the best overall prediction of measured daily mean grass temperature. The 9 a.m. soil temperature was similarly reliable in predicting daily mean soil temperature at both 25 mm and 100 mm depths. The implications of temperature levels on each aspect are discussed in relation to pasture species composition and growth.