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Kalgoorlie, Western Australia

Heating and cooling in KalgoorlieVery dry summer heat, then frost on clear winter nights.

An installer for Kalgoorlie

Licence-checked installers in Kalgoorlie who specialise in your kind of job see it, and the one who takes it calls you to quote.

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Kalgoorlie needs serious cooling and real heating. Summer heat is hot and very dry, with January afternoons averaging 24% humidity, which is what evaporative coolers are built for. Winter nights fall to a July mean minimum of 5.0 degrees and below freezing a few times a year, so a cooler alone won't do.

Kalgoorlie's heating and cooling facts

Summer

Bureau of Meteorology averages put Kalgoorlie's January mean maximum at 33.6 degrees and February's at 32.1. The hottest days come on hot, dry north to north-easterly winds, and the record high is 46.5.

Humidity

Afternoon humidity averages 24% in January and 46% in July. That's drier summer air than Perth Metro's 39%.

Winter

The July mean minimum is 5.0 degrees, and overnight temperatures drop below freezing about four times in a typical winter, on clear nights after a day of cold southerly winds. The record low is -3.4 degrees.

Climate zone

NCC 2016 puts Kalgoorlie-Boulder in zone 4: hot dry summer, cool winter.

Housing

At the 2021 Census, 81.2% of the City of Kalgoorlie-Boulder's occupied homes were separate houses, 15.7% townhouses or semis and 1.3% apartments. 36.7% were rented, against 26.6% in Greater Perth. Boulder has buildings dating back as far as 1882.

Power and gas

Western Power's South West Interconnected System reaches east to Kalgoorlie, with Synergy as the only retailer for households on it. Energy Networks Australia lists Kalgoorlie among the places with ATCO natural gas lines and meters.

The jobs that come up most here

Evaporative cooling. With 24% afternoon humidity in January, Kalgoorlie is strong evaporative country. CHOICE rates evaporative as most effective in hot, dry climates with low humidity, and Seeley says it performs best in hot, dry conditions. It needs some windows open and a water supply, and it only cools.

Heating for frosty nights. Reverse cycle splits or ducted systems, or gas where it's connected, cover winter. For reverse cycle, check the heating capacity at 2 degrees outside on the energy label, as shown on the ACT Government's example label, because Kalgoorlie's clear winter nights go lower than that.

Defrost pauses. On a frosty Kalgoorlie morning, a reverse cycle unit may stop heating for up to 10 minutes while its outdoor unit clears ice. That's the defrost cycle Mitsubishi Electric describes, and no reason to call a repairer.

Servicing through a long summer. Seeley asks for evaporative coolers to be serviced after the first year, then every two years, and more often in harsh environments. Ask your technician whether your conditions count.

Older buildings and rentals

If you're in one of Boulder's older buildings, some dating back to 1882, have the installer inspect the roof space, walls and switchboard before they quote. And with more than a third of Kalgoorlie-Boulder homes rented, many installs start with the owner's written OK.

Who can do the work

In WA, the switchboard protective device and fixed wiring for a new system need a licensed electrical contractor, and refrigerant work needs an ARC licence. In May 2025 the WA Government reported that a business owner was fined after facilitating two split installs and invoicing for them with no electrical contractor's licence, so check the EC number on any quote.

Around Kalgoorlie-Boulder, licence-checked installers who specialise in your kind of job can see it where we have them, and the installer who takes it is the only one who gets your contact details. If no one around Kalgoorlie-Boulder takes it within 48 hours, installers elsewhere in Western Australia may see it too.

What we'd do

What we'd do in Kalgoorlie

We'd cool with evaporative if we were happy to open windows and sort heating separately, because the dry heat suits it so well. If we wanted one system for both seasons, we'd choose reverse cycle and check its heating capacity at 2 degrees before anything else. Either way, we'd want a specialist in that system and an EC number on the quote.

What this work looks like

Photos from real jobs in Melbourne, to show what the work looks like. They aren't from an installer near you.

Lifting a new split system indoor unit into place
Lifting a new split system indoor unit into place. A job in Melbourne.
Fitting a split system's indoor unit onto its wall plate
Fitting a split system's indoor unit onto its wall plate. A job in Melbourne.
New insulated ducts run through a roof space
New insulated ducts run through a roof space. Sep 2023. A job in Melbourne.

More job photos

Questions people ask

Is evaporative cooling a good choice in Kalgoorlie?
For dry summer heat, yes. January afternoons average 24% humidity. It only cools, so you'll still need heating for frosty winter nights. Our evaporative cooling page covers how it works.
Will reverse cycle heating cope with Kalgoorlie frosts?
Good systems can. The ACT Government says they still work at minus 10 degrees, though efficiency changes with the outdoor temperature. Ask for the heating capacity at 2 degrees.
Who's the electricity retailer in Kalgoorlie?
For households on the SWIS, which reaches Kalgoorlie, Synergy is the only retailer. Use your Synergy rate in our running cost tool.
Can I put an air conditioner in a rental?
Only with the owner's agreement. More than a third of Kalgoorlie-Boulder homes are rented, so check before anyone books an install.

Ready for the right installer to take a look in Kalgoorlie?

Your postcode and three quick questions. Licence-checked local installers who specialise in your kind of job see it, and the one who takes it gets in touch to quote.

Free for you. Installers pay us for each job we pass on.

Read next

  1. 01Evaporative coolingHow evaporative cooling works, where it suits, and what a good install involves.
  2. 02Reverse cycle air conditioningHow reverse cycle heats and cools, which type suits your home, and what to check for winter.
  3. 03Evaporative or refrigerated cooling?How each kind of cooling works, why humidity matters, and what each one needs from your home.
  4. 04Gas heater serviceHow often to service a gas heater, the warning signs, and who's licensed to do it.
  5. 05Running cost toolHow much power your unit uses, worked out with your hours and your own rate.
  6. 06Heating and cooling in Western AustraliaWA's electrical contractor rules for new air conditioners, the EC number, gas permits and cooling-off.

Where this information comes from

We don't publish prices. Every home is different, so an installer's written quote is the only real number. How we write and check these pages.

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