Every summer, many Queensland homeowners make the same mistake: they come home to a hot house, turn the air conditioner down to 18°C, and wonder why the next electricity bill is so high.

The problem is not usually the air conditioner itself. It is when you use it and the temperature to set your air conditioner.

With more households in QLD now on time-of-use plans, power is most expensive between 4pm and 9pm. That is exactly when most people turn their aircon on.

The right air conditioner temperature and aircon temperature can make a huge difference to your energy costs. Instead of blasting the system after work, the smarter option is to set your air earlier and pre-cool the house.

For most homes in Queensland, the perfect temperature sits between 24 degrees and 26°C. This is the ideal temperature for balancing comfort and energy efficiency while still keeping your home cool during summer in Australia.

The good news? You do not need to stop using your air con. You simply need a smarter schedule and the best temperature to set your air conditioner.

Why 4–9pm Costs More

Under many Queensland electricity plans:

Off-peak power is cheapest overnight and early morning
Daytime rates are moderate
Peak rates are highest between 4pm and 9pm

During this time, entire neighbourhoods are using:

Air conditioners
Ovens and cooktops
TVs, lights and appliances
Dishwashers and washing machines

Because demand is highest, electricity during these hours can cost two to three times more than during the day.

That means if you wait until 5pm or 6pm to turn your air conditioner on, you are paying the highest rate while forcing the system to cool an already-hot house.

The Biggest Mistake Most Households Make

The most common mistake is coming home to a hot house and setting the air conditioner to 18°C or 20°C.

This does not cool the home faster.

It simply makes the system run harder and longer.

By that point:

Your walls and windows have been heating up all day
The air conditioner has to work much harder
You are paying peak electricity rates

The result is a much higher power bill.

The Best Aircon Schedule and Air Conditioner Temperature in QLD

The best way to reduce your power bill with aircon is to pre-cool your home before peak pricing begins.

2pm–4pm: Pre-Cool the House
Close curtains and any blind facing the afternoon sun
Shut doors to unused rooms
Turn the air conditioner on at 23–24°C
Use a ceiling fan to help move cool air through the home

This cools the home while electricity is still cheaper and helps maintain the set temperature before peak pricing begins.

4pm–6pm: Maintain the Temperature
Increase the setting slightly to 24–25°C
Keep doors and windows closed
Use ceiling fans for extra comfort
6pm–9pm: Use Less During Peak Hours
Raise the temperature to 25–26°C if comfortable
Cool only the rooms you are using
Avoid using dryers, dishwashers and other major appliances until after 9pm
After 9pm

Electricity rates usually drop again, making it a better time to run appliances or lower the temperature slightly if needed.

Why the Best Temperature to Set Your Air Conditioner Is 24–26°C

Many people think lowering the air conditioner to 18°C will cool the home faster. It will not.

An air conditioning system cools at the same speed regardless of what you set the thermostat to. A lower temperature setting simply means the system keeps running for longer, increasing energy consumption and putting more strain on the system.

For most homes, the best air conditioner temperature is between 24 degrees and 26°C. This temperature range is the sweet spot between comfort and energy efficiency.

Why?

It keeps the indoor temperature comfortable without making the room feel too cold
It reduces humidity and humidity levels without overworking the system
It helps reduce your energy bills and running costs
Every degree higher can reduce power use and cooling costs

The ideal air conditioner temperature also depends on the ambient temperature outside. During the summer months, when the actual temperature is much hotter, a higher temperature indoors still feels comfortable because your air conditioner is removing warm air and humidity.

If you want maximum efficiency, set the temperature between 24°C and 26°C and let the system maintain the set temperature instead of constantly changing it.

Use a Ceiling Fan to Save Energy

A ceiling fan is one of the easiest ways to save energy when running an air conditioner.

The fan improves air flow and airflow, helping cool air more effectively move around the room. This allows you to set the air a little higher while still feeling comfortable.

For example, if 24°C feels slightly warm, try 26°C with a ceiling fan. Many people find it feels just as cool because the fan helps make the air circulate.

That small change can improve energy savings, reduce your energy use and lower your electricity bill.

Smart Thermostat Settings That Work

If your air conditioner has a timer or smart controls, set it to run automatically:

2:30pm – Turn on at 24°C
4:00pm – Increase to 25°C
6:30pm – Increase to 26°C
9:00pm – Return to your preferred setting

This is one of the simplest ways to avoid the QLD 4–9pm electricity trap.

Extra Tips for Maximum Efficiency

To get the best air conditioner and air conditioning performance:

Clean air filters regularly and book regular maintenance or a service before summer
Seal gaps around windows and doors to stop cool air from escaping and hot air entering
If you have a ducted system, only cool the areas during the day that you are using
Use your thermostat timer so temperature drops happen before 4pm, not after
Choosing the best size to suit your home will help you buy a more energy-efficient air conditioner
Delay using high-power appliances until after 9pm to reduce home energy demand and money and energy wasted
The Bottom Line

The best aircon schedule in QLD is not to wait until you get home and blast the system.

Instead:

Pre-cool before 4pm
Keep the temperature around 24–25°C
Use ceiling fans
Raise the setting slightly during peak hours

These simple changes can help you stay comfortable while cutting your power bill.

If your air conditioner still struggles to keep the house cool, it may need servicing or it may not be the right size for your home.

At Wahoo Air Conditioning, we help Queensland homeowners choose more efficient systems, improve cooling performance and lower their running costs.

If your current system is struggling, costing too much to run or simply not keeping your home comfortable, getting the right advice can save you far more than simply turning the temperature down.