Thirroul – current water temperature and swimming conditions

Water Temperature in Thirroul: 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 Thirroul declined overall during the past month, they have shown a noticeable rebound over the last week.

According to our forecast, Sea water temperature in Thirroul 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

Thirroul sits along the Illawarra coastline, where a broad stretch of sand meets the open waters of the Tasman Sea beneath the escarpment. Water temperatures here follow the familiar seasonal rhythm of the New South Wales coast. In summer, from December to March, the sea is usually at its warmest, around 21–24 °C, which is comfortable for most swimmers without a wetsuit. Autumn brings a gradual cool-down to roughly 19–21 °C. Winter is the coldest period, with water temperatures typically between 16–18 °C, while spring sees a steady warm-up into the 18–20 °C range as ocean currents and air temperatures begin to lift.