The hottest month in Sydney is January when the average maximum temperature is 27°, average temperature is 23° and average minimum temperature is 19°.
The coolest month in Sydney is July when the average maximum temperature is 17°, average temperature is 13° and average minimum temperature is 9°.
The longest days in Sydney are in December, with an average of 14.4 hours of daylight per day. June has the shortest days with an average of 9.9 hours of daylight per day.
The sunniest days in Sydney are in December which has the most hours of sunshine per day with an average of 11.1 hours of sunshine per day, making it a very sunny and pleasant month with long bright days. July has the least sunshine with an average of 7.8 hours of sunshine per day, making it a quite sunny month with some cloud cover.
The ultraviolet index is the highest in January when it reaches 13.8 and lowest in June when it reaches 2.6.
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 Sydney are found in January when they peak at 23° and lowest in September when they dip to 18°.
The sea is best for swimming between December and May when the temperature is above 21° which is comfortable for swimming though some may prefer warmer water.
The wettest month in Sydney is June with 34.1cm of rain and November has the most days of rain with 16.1 days with some rain, a wet time to visit the beach.
The driest month in Sydney is January with 5.3cm of rain and August has the fewest days of rain with 10.4 days with some rain, a slightly wet time to visit the beach.
The most humid month in Sydney is January with a dew point (an indicator of humidity) of 19° which is somewhat uncomfortable for most people in cities but fine on a beach.
The least humid month in Sydney is July with a dew point of 9° which is a bit dry for some.
The most windy month in Sydney is December when the average maximum windspeed is 38kmh and the average wind speed is 20kmh.
The least windy month in Sydney is May when the average maximum windspeed is 29kmh and the average wind speed is 17kmh.