Port Denison – current water temperature and swimming conditions

Water Temperature in Port Denison: 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 Port Denison 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 Port Denison will be 21.5°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

Port Denison sits alongside Dongara on Western Australia’s mid-west coast, facing the Indian Ocean with a mix of open shoreline and more sheltered waters near the harbour and river mouth. Water temperatures here are generally warmer than further south, making swimming appealing for much of the year. In summer, from December to February, the sea usually ranges between 22–25°C, often feeling comfortably warm rather than cool. Autumn remains pleasant at around 20–23°C, while winter brings a mild drop to roughly 17–19°C, still suitable for regular swimming. Spring sees a steady rise again, typically sitting between 19–22°C as air temperatures and sunshine increase.