Dealing with Humidity During Australia's Wet Season

Australia's wet season brings dramatic rainfall, high humidity, and unique challenges for homeowners. From the tropical monsoons of the Top End to the humid summers of coastal Queensland and the damp winters of the south, managing extreme humidity requires preparation, the right equipment, and consistent effort.

Understanding Australia's Wet Season Patterns

Australia experiences different wet season patterns depending on location. In tropical northern Australia, including Darwin, Cairns, and the Top End, the wet season runs from November to April, bringing monsoonal rains and humidity regularly exceeding 80%. This is when the famous "build-up" occurs, with oppressive humidity building for weeks before the monsoon breaks.

Coastal Queensland from Brisbane to Townsville experiences humid subtropical summers with regular tropical storms and cyclone threats. Humidity frequently exceeds 70% from December through March. Sydney and other east coast cities face humid summer conditions, while Melbourne, Adelaide, and Tasmania experience their humidity challenges during the cooler, damper winter months.

Understanding your local pattern is essential for timing your humidity control preparations and knowing when to increase your vigilance.

Preparing Your Home Before Wet Season

Preparation before the wet season arrives makes management during the humid months much easier. Start your preparations several weeks before humidity typically increases in your area.

Inspect and Repair

Check your roof for damaged or missing tiles that could allow water ingress. Clean gutters and downpipes to ensure water drains away from your home. Inspect window and door seals for deterioration. Check for any cracks in external walls that could allow moisture penetration. Fix any existing leaks, no matter how minor.

Service Your Equipment

Service your air conditioning system before heavy use begins. Clean or replace dehumidifier filters. Test that all exhaust fans are working properly. Check that continuous drainage systems are clear and functioning.

Stock Up

Ensure you have adequate supplies of filter replacements, mould cleaning products, and moisture absorbers for enclosed spaces. During peak wet season, these items can become scarce in stores.

Daily Habits During Wet Season

Consistent daily practices are crucial during high-humidity periods. These habits may seem simple, but their cumulative effect is significant.

Maximise Air Conditioning

Run your air conditioning regularly during humid periods, even if temperatures aren't particularly hot. Air conditioning removes moisture as a byproduct of cooling. The "dry" mode on many units prioritises dehumidification with minimal cooling. Keep doors and windows closed while AC is running to prevent humid outdoor air from entering.

Run Dehumidifiers Continuously

During extreme humidity, run dehumidifiers on continuous operation rather than relying on the humidistat. In tropical conditions, you're essentially fighting a constant battle against the outdoor humidity trying to equalise with your indoor environment. Set up continuous drainage so you don't need to empty tanks constantly.

Ventilate Strategically

Unlike in moderate climates, opening windows during wet season often makes things worse by allowing humid air inside. Only ventilate when outdoor humidity is genuinely lower than indoors, typically early morning in some regions. Otherwise, keep your home sealed and rely on mechanical dehumidification.

Manage Moisture-Generating Activities

Every activity that generates moisture adds to your dehumidification burden. Use rangehood exhaust fans whenever cooking. Keep bathroom doors closed during showers and run exhaust fans for at least 30 minutes afterward. Avoid drying clothes indoors. Cover fish tanks. Limit the number of indoor plants.

Problem Areas During Wet Season

Wardrobes and Closets

Enclosed spaces with limited air circulation are particularly vulnerable. Mould can establish on clothing, shoes, and bags before you notice it. Leave wardrobe doors slightly ajar for air circulation. Place moisture absorbers or a small dehumidifier in walk-in robes. Avoid cramming items too tightly; allow air to flow between garments.

Under-House Spaces

Homes on stumps or with crawl spaces face particular challenges. Ground moisture evaporates into these spaces and can migrate into the home above. Ensure adequate ventilation beneath the house. Consider installing a vapour barrier on exposed soil. Inspect regularly for standing water or excessive dampness.

Garages and Storage

Items stored in garages and sheds are vulnerable to humidity damage. Store valuable items in sealed containers with moisture absorbers. Ensure adequate ventilation. Consider running a dehumidifier in enclosed garages, particularly if they contain vehicles, tools, or stored belongings.

Equipment for Extreme Humidity

Standard dehumidifiers may struggle in extreme conditions. For wet season in tropical areas, consider these factors:

Capacity

Choose a dehumidifier rated for at least one size category larger than your space. A unit rated for 40m² may only manage 25m² during extreme humidity. Having extra capacity allows the unit to run less continuously while still maintaining control.

Continuous Drainage

At peak extraction, a dehumidifier might fill its tank every few hours. Continuous drainage via gravity or pump eliminates the need for constant emptying and ensures the unit never stops working because of a full tank.

Commercial Grade

For particularly challenging environments, commercial dehumidifiers offer higher capacity, more robust construction, and often better efficiency. While more expensive, they're designed for continuous operation in demanding conditions.

Multiple Units

In larger homes or extremely humid conditions, multiple smaller units may be more effective than one large unit. Place them in different zones to ensure even humidity control throughout your home.

Protecting Valuables

Some items require extra protection during wet season:

Electronics

Humidity can damage circuit boards, corrode contacts, and cause malfunctions. Keep electronics in climate-controlled areas. Consider using silica gel packets around sensitive equipment. Allow devices to acclimatise before turning them on if moved from air-conditioned to non-air-conditioned spaces.

Documents and Photos

Paper is extremely susceptible to humidity damage. Store important documents in sealed containers with desiccants. Consider digitalising irreplaceable photos and documents as backup.

Musical Instruments

Wooden instruments are particularly sensitive to humidity fluctuations. Store in cases with humidity control devices. Keep in climate-controlled rooms. Consult manufacturer guidelines for acceptable humidity ranges.

Leather and Textiles

Leather goods, expensive fabrics, and traditional textiles can quickly develop mould in humid conditions. Store in breathable bags with moisture absorbers. Check regularly during wet season.

After the Wet Season

When the wet season ends, don't let your guard down immediately. Moisture accumulated in building materials can take weeks to dry out. Continue running dehumidifiers until humidity levels consistently stabilise. Open up your home to fresh air when conditions allow. Inspect thoroughly for any mould that may have established during the humid months. Clean and service all humidity control equipment before storage. Address any damage or maintenance issues discovered during the wet season while conditions are favourable.

Living successfully in Australia's humid regions requires accepting humidity management as an ongoing responsibility rather than an occasional task. With preparation, the right equipment, and consistent effort, you can maintain a comfortable, healthy home even through the most challenging wet season conditions.