Cape Northumberland – current water temperature and swimming conditions

Water Temperature in Cape Northumberland: 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 Cape Northumberland 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 Cape Northumberland 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

Cape Northumberland marks the south-eastern tip of South Australia, where the coastline faces directly into the open waters of the Great Australian Bight. This exposed position keeps water temperatures cool throughout the year. In summer, the sea is usually at its warmest, generally ranging from about 17–20°C, which still feels brisk but can be refreshing on hot days. Autumn brings a gradual cooling to roughly 15–18°C, while winter is distinctly cold, often around 12–14°C. Spring warms slowly, with water temperatures commonly sitting between 13–16°C, and sudden changes can occur after strong southerly weather.