1 During summer average high temperatures are 27.7°C (81.8°F) and average low temperatures are 24°C (75.2°F). 2  Come autumn/ fall temperatures decrease achieving average highs of 26°C (78.8°F) during the day and lows of 22°C (71.6°F) generally shortly after sunrise. The average annual temperature is 21.8 degrees Celsius (71.2 degrees Fahrenheit). 2  See the temperatures page for a monthly breakdown and the fixed scale graph. 3  Average monthly temperatures vary by 9.5 °C (17.1°F). 4  This indicates that the continentality type is hyperoceanic, subtype barely hyperoceanic.