Lake Joondalup – current water temperature and swimming conditions
This page provides information about the current water temperature at Lake Joondalup in Western Australia. Here you can view recent temperature trends on a 30-day chart, check typical monthly water temperature ranges, and compare today’s reading with historical averages for this date. A 7-day water temperature forecast, local weather conditions, and an overview of swimming suitability are also included.
Current Water Temperature
The water temperature in Lake Joondalup today is 21°C.
Water Temperature in Lake Joondalup: Daily Trends, Historical Records, and Forecast
✅ Lake water between 20 and 25°C offers very comfortable swimming conditions for most people. Combined with warm air temperatures and calm weather, this range is ideal for extended swims and family activities. Because lakes lack strong currents, the water often feels gentler and warmer than rivers. Even with light cloud cover, swimming remains enjoyable.
Water Temperature Over the Last 30 Days
While water temperatures in Lake Joondalup declined overall during the past month, they have shown a noticeable rebound over the last week.
According to our forecast, the water temperature in Lake Joondalup will be 19.1°C in the next 7 days. See the table below for daily data for the upcoming week.
Table of Daily Water Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| Aug 14 | 21.1°C | 18.8°C | |
| Aug 15 | 21.2°C | 18.8°C | |
| Aug 16 | 20.9°C | 18.8°C | |
| Aug 17 | 20.8°C | 18.8°C | |
| Aug 18 | 21.0°C | 18.8°C | |
| Aug 19 | 20.9°C | 18.8°C | |
| Aug 20 | 20.9°C | 18.8°C | |
| Aug 21 | 21.0°C | 18.8°C | |
| Aug 22 | 21.0°C | 18.8°C | 21.0°C |
| Aug 23 | 18.8°C | 20.7°C | |
| Aug 24 | 18.8°C | 20.5°C | |
| Aug 25 | 18.8°C | 20.2°C | |
| Aug 26 | 18.8°C | 19.9°C | |
| Aug 27 | 18.8°C | 19.6°C | |
| Aug 28 | 18.8°C | 19.4°C | |
| Aug 29 | 18.8°C | 19.1°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual lake water temperatures may differ from the reported values by several degrees, particularly during periods of strong winds or rapid weather changes. Wind can mix surface and deeper layers in a lake, bringing cooler water to the surface, while shallow areas may warm more quickly under direct sunlight. Air temperature, sunshine, and cloud cover strongly influence how quickly a lake heats up or cools down. These factors can lead to noticeable temperature variations across different parts of the lake.
Our forecast is based on a proprietary mathematical model that considers real-time lake temperature observations, historical trends, seasonal cycles, wind strength and direction, and region-specific air temperature. To enhance accuracy, we also incorporate data from nearby monitored locations and comparable lakes within Australia.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Today | Yesterday | A Week Ago |
|---|---|---|---|
| January | 18°C | 23°C | 32°C |
| February | 18°C | 23°C | 33°C |
| March | 18°C | 22°C | 33°C |
| April | 18°C | 21°C | 27°C |
| May | 14°C | 18°C | 21°C |
| June | 12°C | 18°C | 22°C |
| July | 11°C | 18°C | 22°C |
| August | 13°C | 19°C | 22°C |
| September | 14°C | 19°C | 22°C |
| October | 16°C | 20°C | 26°C |
| November | 19°C | 22°C | 33°C |
| December | 18°C | 22°C | 33°C |
Location & Local Information
Lake Joondalup sits north of Perth within a chain of coastal wetlands and is shaped by seasonal rainfall and the region’s Mediterranean climate. Being shallow, the lake’s water temperature responds quickly to air temperature and sunshine. In summer, the water can warm to around 20–26°C, sometimes feeling quite warm during prolonged hot spells. Spring and autumn are milder, usually sitting between 16–20°C, while winter temperatures commonly drop to about 12–15°C, giving the lake a cool feel, especially after cold nights. Wind and cloud cover can cause noticeable day-to-day changes, so conditions are rarely consistent for long.
Swimming Conditions
Swimming in Lake Joondalup is generally not allowed and not recommended. Although summer water temperatures may appear suitable, the lake is managed primarily as a conservation wetland rather than a recreational water body. Water quality can vary due to nutrient levels, urban runoff, and periods of algal growth, particularly in warmer months. The lake is also an important habitat for birdlife and other wildlife, and human swimming would disturb the ecosystem. After rainfall, conditions often deteriorate further, with reduced clarity and cooler water. Overall, Lake Joondalup is best appreciated for walking, cycling, and nature observation, with its seasonal water temperatures noted but swimming avoided in favour of safer, managed beaches and rivers nearby.