Loch McNess – current water temperature and swimming conditions
This page provides information about the current water temperature at Loch McNess 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 Loch McNess today is 18°C.
Water Temperature in Loch McNess: Daily Trends, Historical Records, and Forecast
⚠️ A lake temperature of 15 to 20°C is considered cool to comfortable for swimming in Australia. On warm days with light winds, this range allows for relaxed swimming, especially in shallow or sheltered areas. Comfort depends strongly on air temperature and sunshine, as cooler or overcast weather can still make the water feel chilly. This range is common during spring and early summer.
Water Temperature Over the Last 30 Days
Water temperatures in Loch McNess have been on a steady rise over the past month and have continued to climb over the last week.
According to our forecast, the water temperature in Loch McNess will be 19.4°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 |
|---|---|---|---|
| Jun 13 | 13.2°C | 19.3°C | |
| Jun 14 | 13.4°C | 19.3°C | |
| Jun 15 | 15.7°C | 19.3°C | |
| Jun 16 | 15.6°C | 19.3°C | |
| Jun 17 | 15.4°C | 19.3°C | |
| Jun 18 | 15.4°C | 19.3°C | |
| Jun 19 | 17.1°C | 19.3°C | |
| Jun 20 | 17.3°C | 19.3°C | |
| Jun 21 | 17.6°C | 19.3°C | 17.6°C |
| Jun 22 | 19.3°C | 17.9°C | |
| Jun 23 | 19.3°C | 18.1°C | |
| Jun 24 | 19.3°C | 18.4°C | |
| Jun 25 | 19.3°C | 18.7°C | |
| Jun 26 | 19.3°C | 18.9°C | |
| Jun 27 | 19.3°C | 19.2°C | |
| Jun 28 | 19.3°C | 19.4°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 | 20°C | 31°C |
| February | 18°C | 20°C | 32°C |
| March | 18°C | 20°C | 29°C |
| April | 15°C | 18°C | 21°C |
| May | 13°C | 16°C | 17°C |
| June | 10°C | 19°C | 22°C |
| July | 10°C | 19°C | 22°C |
| August | 11°C | 19°C | 22°C |
| September | 13°C | 20°C | 22°C |
| October | 16°C | 20°C | 22°C |
| November | 19°C | 20°C | 31°C |
| December | 18°C | 20°C | 33°C |
Location & Local Information
Loch McNess is a shallow freshwater lake within Yanchep National Park, north of Perth, and its water temperature reflects the local Mediterranean climate and groundwater influence. Because the lake is shallow, temperatures respond quickly to seasonal conditions. In summer, the water commonly warms to around 20–25°C, which can feel quite mild on hot days. Spring and autumn usually sit between 16–20°C, offering cooler but still moderate conditions. During winter, water temperatures often drop to about 12–15°C, giving the lake a noticeably cool feel, particularly in the mornings and after cold nights. Cloud cover and wind can also affect how warm the water feels from day to day.
Swimming Conditions
Swimming in Loch McNess is generally not recommended. While summer water temperatures may appear suitable, the lake is managed primarily for conservation and passive recreation rather than swimming. Water quality can vary due to nutrient levels, natural organic matter, and limited circulation, which can reduce clarity at times. The lake is also an important habitat for wildlife, including birds and aquatic species, and human swimming is discouraged to protect the environment. After rainfall, conditions can worsen further, with cooler water and reduced quality. Overall, Loch McNess is best enjoyed for walking, picnicking, and wildlife viewing, with its seasonal water temperatures noted but swimming avoided in favour of safer, designated waterways elsewhere in the region.