Clontarf – current water temperature and swimming conditions

Water Temperature in Clontarf: Daily Trends, Historical Records, and Forecast

⚠️ This is cool water that may feel brisk on entry. Swimming is usually limited to short sessions, and prolonged stays can become uncomfortable without thermal protection. Many swimmers choose a wetsuit, especially for surfing or open-water swimming.

It’s important to note that these swimming tips and recommendations apply only in settled weather. When air temperatures drop below 20°C — and sometimes even below 25°C — swimming can feel uncomfortable, even when water temperatures are relatively high.

Water Temperature Over the Last 30 Days

While water temperatures in Clontarf declined overall during the past month, they have shown a noticeable rebound over the last week.

According to our forecast, Sea water temperature in Clontarf will be 18.1°C in the next 7 days. See the table below for daily data for the upcoming week.

Table of Daily Sea Temperature Data

Annual Water Temperature Overview by Month

Monthly Water Temp Ranges

30°C

25°C

20°C

15°C

10°c

5°C

0°C

Annual Water Temperature Trend

Clontarf sits on Sydney’s northern shoreline, tucked inside the harbour system that connects to the Tasman Sea, and its water temperatures tend to be a little more stable than on the open coast. In summer, the water usually warms to around 22–25 °C, making it very comfortable for swimming and spending time in the water. Autumn often stays pleasant, with temperatures commonly between 20–23 °C, while spring is cooler at roughly 18–21 °C as the harbour gradually warms after winter. During winter, water temperatures typically drop to about 16–18 °C, which feels cool but is still swimmable for short dips, especially on sunny days with light winds.