St. Helena Bay normally receives about 204mm of rain per year and because it receives most of its rainfall during winter it has a Mediterranean climate. The chart below (lower left) shows the average rainfall values for St. Helena Bay per month. It receives the lowest rainfall (1mm) in February and the highest (40mm) in June. The monthly distribution of average daily maximum temperatures (centre chart below) shows that the average midday temperatures for St. Helena Bay range from 16.6°C in July to 25.6°C in February. The region is the coldest during July when the mercury drops to 7.9°C on average during the night. Consult the chart below (lower right) for an indication of the monthly variation of average minimum daily temperatures.