The hottest month in Waiheke Island is February when the average maximum temperature is 24°, average temperature is 20° and average minimum temperature is 17°.
The coolest month in Waiheke Island is July when the average maximum temperature is 14°, average temperature is 11° and average minimum temperature is 8°.
The longest days in Waiheke Island are in December, with an average of 14.7 hours of daylight per day. June has the shortest days with an average of 9.7 hours of daylight per day.
The sunniest days in Waiheke Island are in December which has the most hours of sunshine per day with an average of 7.2 hours of sunshine per day, making it a quite sunny month with some cloud cover. May has the least sunshine with an average of 4 hours of sunshine per day, making it not a particularly sunny month.
The ultraviolet index is the highest in January when it reaches 13.1 and lowest in June when it reaches 2.
An ultraviolet index reading above 11 indicates an extreme risk of harm from unprotected sun exposure. Unprotected skin risks burning in less than 10 minutes. Take all precautions because unprotected skin and eyes can burn in minutes. Tanning will be safest before 10am and after 4pm but only with a good application of sun screen. For those with sensitive skin stay in the shade and wear protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days. Watch out for relections from water that may increase ultraviolet exposure.
The warmest sea water temperatures in Waiheke Island are found in February when they peak at 20° and lowest in August when they dip to 13°.
The sea is best for swimming between December and May when the temperature is above 16° which is cool for swimming, shorty wetsuit may help you extend your time in the water.
The most humid month in Waiheke Island is February with a dew point (an indicator of humidity) of 18° which is OK for most but slightly uncomfortable for some.
The least humid month in Waiheke Island is July with a dew point of 11° which is very comfortable.
The most windy month in Waiheke Island is October when the average maximum windspeed is 34kmh and the average wind speed is 19kmh.
The least windy month in Waiheke Island is April when the average maximum windspeed is 26kmh and the average wind speed is 14kmh.