By and large, Newhaven is hot and dry in summer and cool and dry in winter. Mean daily maximum temperatures from November - February are 33 - 36°C and from June - August are 22 - 25 °C. Mean daily minimum temperatures of 20 - 22.5 °C occur during November - February and 7.5 - 8.5 °C during June-August. The prevailing wind is from the south-east.
Annual average rainfall is 340mm; though rainfall is highly variable from year to year, with an annual range from 66 to 951mm recorded between 1962 and 2001. Heavy rainfall events following a succession of dry years are an important determinant of plant reproduction and subsequent wildfire risk.