Perth South Coast – Water Temperature Overview
This page provides information on Perth South Coast locations where sea water temperature data is available, including current conditions, monthly ranges and historical records.
Current Water Temperature
The current water temperature in the Perth South Coast today is within the range of 21-22°C. Thus, the average water temperature is about 22°C. 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.
Sea Temperature Trends
Over the past month, the sea water temperature has remained largely unchanged. Overall, the sea water temperature is within the range expected based on historical data for this month.
Water Temperature and Swimming Conditions by Month
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 18°C | 21°C | 24°C |
| February | 19°C | 22°C | 25°C |
| March | 19°C | 22°C | 25°C |
| April | 18°C | 21°C | 24°C |
| May | 19°C | 22°C | 24°C |
| June | 17°C | 20°C | 22°C |
| July | 16°C | 19°C | 22°C |
| August | 17°C | 19°C | 20°C |
| September | 16°C | 18°C | 20°C |
| October | 16°C | 19°C | 21°C |
| November | 16°C | 19°C | 21°C |
| December | 17°C | 20°C | 23°C |
The Perth South Coast stretches south of Perth through areas such as Rockingham, Safety Bay and Shoalwater Bay, facing the Indian Ocean but benefiting from a relatively sheltered coastal layout. Sea water temperatures here are moderate by Western Australian standards and show clear seasonal variation. During summer, water temperatures typically range from about 20°C to 23°C, creating comfortable conditions for swimming, especially on warm, calm days. Autumn often remains pleasant, with sea temperatures around 18–21°C before cooling further in winter. In winter, water temperatures usually sit between 16°C and 18°C, which can feel cool on entry but are still manageable for many swimmers, particularly when the weather is sunny. Spring brings a gradual warming trend, with temperatures rising back toward the high teens and low 20s°C.
Swimming Conditions
Swimming is allowed and widely enjoyed along the Perth South Coast, thanks to sandy beaches, gentle gradients and generally calmer conditions compared with more exposed sections of the WA coastline. Summer and early autumn are the most popular times for swimming, when warmer water allows for longer and more relaxed sessions in the sea. Sheltered bays and inlets provide suitable conditions for families and casual swimmers, as well as for snorkelling and paddling. In winter, swimming continues among locals and regular ocean users, although some people prefer shorter swims or use wetsuits for added comfort. Overall, the Perth South Coast offers reliable swimming opportunities for much of the year, supported by moderate sea water temperatures, accessible beaches and favourable coastal conditions.