Cat Bay – current water temperature and swimming conditions

Water Temperature in Cat Bay: Daily Trends, Historical Records, and Forecast

⚠️ Water in this range feels cool but still manageable for many swimmers. Short to moderate swims are comfortable, especially in warm weather. Some people may prefer a wetsuit for longer stays, particularly when swimming actively or outside peak summer conditions.

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

Water temperatures in Cat Bay have been gradually cooling over the past month, with a further drop recorded during the last week.

According to our forecast, Sea water temperature in Cat Bay will be 19.0°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

Cat Bay sits on the northern side of Phillip Island, looking out over the Bass Strait, and its water temperatures reflect the cooler conditions of Victoria’s southern coastline. In summer, the sea usually warms to around 18–22 °C, which feels refreshing but comfortable for swimming on warm, sunny days. Autumn often remains mild, with water temperatures commonly between 16–20 °C, while spring is cooler at roughly 14–18 °C as the water gradually warms after winter. During winter, temperatures typically drop to about 11–14 °C, which feels quite cold and generally limits swimming to short dips or those wearing wetsuits.