Diamond Beach – current water temperature and swimming conditions

Water Temperature in Diamond Beach: 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 Diamond Beach 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 Diamond Beach will be 20.3°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

Diamond Beach, in the Mid-Coast Council area of New South Wales, sits along the open edge of the Tasman Sea and has water temperatures that shift steadily with the seasons. Summer brings the warmest conditions, with the ocean usually ranging from about 22–26 °C, which feels comfortable for extended swims. In autumn, the sea cools slightly to around 20–23 °C, still pleasant for most swimmers. Winter is cooler but far from harsh, with temperatures typically between 17–20 °C, while spring sees a gradual warm-up from roughly 18 °C into the low twenties as calmer weather returns.