Castletown – current water temperature and swimming conditions

Water Temperature in Castletown: 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 Castletown 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 Castletown will be 21.4°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

Castletown sits just east of Esperance, along a stretch of coastline known for clean water and steady southern swells rolling in from the Great Australian Bight. Sea temperatures here are cool but fairly consistent through the year. In summer, from December to February, the water usually ranges between 18–21°C, which feels comfortable on warm, sunny days. Autumn brings a gentle drop to around 16–19°C, while winter is the coldest period, commonly sitting at 13–15°C. Spring slowly warms again, typically reaching 15–17°C, though cool winds can still make the water feel brisk.