The Moreland Council hot and cold weather policy can be found on the Moreland City Council website here - scroll down and look for Outdoor Pool Hot and Cold Weather Policy. As we can't link to it directly, here is another way to read it.
Policy - Outdoor Swimming Pools - Hot and Cold Weather
Due to community pressure, the normal weekday opening closing time for the pool has been extended to 7.00pm. However, there is scope for the pool to be open even later in hot weather and to quote from the opening hours policy for hot and cold weather, "the planning trigger for considering extension of hours for the next day is when the Bureau of Meteorology weather forecast at mid afternoon for the next day is for a 32 degrees Celsiusm aximum or higher. This forecast will be monitored early each day to determine if there has been significant change of forecast on the day.The trigger for extension of evening hours on any day is when the temperature is 32 degrees Celsius or higher at 4pm according to the latest Bureau of Meteorology weather observationson that day, and there is reasonable patronage in the water (greater than 25 patrons one hour prior to usual scheduled closing) and numbers in the water are maintained at 25 or more. The rationale for specifying patronage ‘in the water’ is to avoid extension of hours simply because patrons want to remain in the grounds, without using the pools.When extension of hours is not feasible due to staffing constraints and/or occupational health and safety issues, including inadequate lighting, consultation must occur no later than 5pm on the day extension of hours is being considered between the centre manager and Council’s Aquatic Facilities Unit."
So basically, when the forecast is for more than 32C and there are at least 25 people in the pool, then extended opening hours need to be considered.