Thistle Island – current water temperature and swimming conditions

Water Temperature in Thistle Island: 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

Water temperatures in Thistle Island 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 Thistle Island will be 15.5°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

Thistle Island sits off the west coast of the Eyre Peninsula within Spencer Gulf, and its water temperatures reflect a mix of sheltered gulf conditions and nearby open ocean influence. In summer, the sea is at its most comfortable, usually ranging from about 18–22°C, which feels cool but pleasant on warm days. Autumn brings a gradual cooling to roughly 16–19°C, while winter is noticeably colder, often around 13–15°C. Spring sees a steady warm-up, with water temperatures commonly sitting between 15–18°C, shaped by sunshine, wind and changing sea conditions around the island.