Semaphore – current water temperature and swimming conditions

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

✅ This water feels mild to warm and is comfortable for the majority of swimmers. Swimming is enjoyable, though longer stays may feel cooler for some people, especially in windy conditions. These temperatures are well suited to family outings and active swimming, particularly on warm days.

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

Over the past 30 days, water temperatures in Semaphore have generally increased, although a slight cooling trend has set in over the last week.

According to our forecast, Sea water temperature in Semaphore will be 20.5°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

Semaphore sits on Adelaide’s north-western coastline, looking out over the waters of the Great Australian Bight, and its sea temperatures follow a clear and gentle seasonal pattern. In summer, the water is at its warmest and most inviting, usually around 20–23°C, making it comfortable for swimming during hot days. Autumn brings a gradual cooling to roughly 18–21°C, while winter is noticeably cooler, often sitting between 14–16°C. Spring marks a steady warm-up, with water temperatures commonly ranging from 16–19°C, influenced by sunshine, light winds and calmer weather spells.