The hottest month in Cairns is December when the average maximum temperature is 31°, average temperature is 28° and average minimum temperature is 24°.
The coolest month in Cairns is August when the average maximum temperature is 27°, average temperature is 22° and average minimum temperature is 17°.
The longest days in Cairns are in December, with an average of 13.1 hours of daylight per day. June has the shortest days with an average of 11.1 hours of daylight per day.
The sunniest days in Cairns are in December which has the most hours of sunshine per day with an average of 6.2 hours of sunshine per day, making it a quite sunny month with some cloud cover. May has the least sunshine with an average of 4.3 hours of sunshine per day, making it a sunny month that is overcast at times.
The ultraviolet index is the highest in February when it reaches 16 and lowest in June when it reaches 7.4.
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 Cairns are found in February when they peak at 29° and lowest in August when they dip to 25°.
The sea is best for swimming between December and May when the temperature is above 27° which is very warm and ideal for relaxing and swimming for the whole day.
The wettest month in Cairns is April with 45.5cm of rain and March has the most days of rain with 22.4 days with some rain, a very wet time to visit the beach.
The driest month in Cairns is August with 2.8cm of rain and the least days of rain with 8.7 days with some rain, a dry time to visit the beach.
The most humid month in Cairns is February with a dew point (an indicator of humidity) of 25° which is very uncomfortable and fairly oppressive unless you are on a beach. At night you would most likely require airconditioning.
The least humid month in Cairns is August with a dew point of 17° which is OK for most but slightly uncomfortable for some.
The most windy month in Cairns is April when the average maximum windspeed is 30kmh and the average wind speed is 17kmh.
The least windy month in Cairns is January when the average maximum windspeed is 25kmh and the average wind speed is 12kmh.