How to handle the heat with hot-weather painting solutions

In an ideal world, summer outdoor temperatures would always hover around 25 degrees, humidity would settle at 50 per cent and a gentle breeze would temper the air. Painters’ heaven! Truth be told, the warmer months in most Australian states are intensely hot and sticky, making painting projects especially challenging for contractors. Demand for painting services spikes during summer so the heat is on for busy professionals.

Whether you’re painting a period weatherboard cottage or a sprawling commercial structure, the right approach and insights can help you paint efficiently, avoid heat stroke and create a lasting impression clients will love. Keep your cool by following these steps.

Prioritise prepping and priming

Once you’ve tested the surface to make sure it is safe (lead free for pre-1970 buildings) and sound, prep it. Removing all debris ahead of time means a cleaner, smoother surface. And don’t skimp on priming! Apply an exterior-grade primer evenly and let it dry completely before painting. These simple steps create the ideal base for your topcoats and enhance your paint job’s durability.

Plan your painting wisely

A weather app is a painter’s best friend. Check the forecasts constantly to help you schedule your work during the cooler parts of the day. Temperatures above 35 degrees cause paint to dry faster, leading to blistering, peeling, poor adhesion and unsightly stroke marks. Take advantage of daylight savings (if you’re not in Queensland or WA). Paint during early mornings or late afternoons to minimise the adverse effects of heat and sun exposure on the paint – and your health!

Your weather app will also help you navigate temperamental whiplash weather if your state is prone to summer storms. Painting on windy or dusty days can cause small particles to stick to the surface, affecting paint adhesion.

Chase the shade

Strong direct sunlight and high UV rays can put your paintwork under extreme pressure. Cloudy or overcast days are ideal for painting outdoors. But if the sun is shining bright (above 25 degrees), it’s a good idea to start ahead of the sun and work your way around the building, staying ahead of the sun as you go.

You can also avoid the paint drying too quickly in the heat by dividing your project into smaller sections. Focus on one area at a time and finish it before you move on to the next area. As well as preventing paint from drying out prematurely, this method will give you a consistent finish.

Bunnings Trade paint expert Tish Stewart points out that adding water-based additives to your paint such as an acrylic paint conditioner is another way to slow down the drying time. “These products can improve the performance of acrylics and other water-based paints by making them flow like oil in hot, windy weather – without the usual clean-up hassle,” she says. “These conditioners give a longer wet edge, increased coverage and hiding, easier flow and extended spray gun life.”

Get a handle on humidity

Moisture-filled air can extend the drying time of paint, making it sticky and prone to dust and insects, as well as mould and bubbling. Once these bubbles burst the new coats of paint will start to peel off – and you’re likely to get a call from your client!

Remember to check your weather app to avoid painting on days with high humidity or chance of rain. The ideal humidity range for exterior painting is between 40 and 70 per cent.

Be smart with solar-repelling paints

If your client is keen on a trending slate blue, deep charcoal or black exterior, you might want to offer advice from the Australian Standard AS/NZS 2311 Guide: “The application of very dark coloured paints may result in a more rapid deterioration due to the extra heat absorbed; for example, blistering of coating systems on timber or more rapid chalking”.

Alternatively, Tish says you can go with a darker shade of paint if you choose one that contains in-built tech addressing sun damage. “A premium, self-priming paint featuring UV barrier technology, developed especially for professional painters, is the perfect solution,” she says. “These fast-drying, water-based enamel formulas also contain dirt-shedding properties, helping surfaces stay cleaner and protected in tough Australian conditions.” 

Heat-repelling paints are also a smart, sustainable investment. They reflect up to 50 per cent more solar radiation compared to standard paints from 10 years ago. These clever coats can even lower indoor temperatures by up to 6 degrees in hot weather, cutting cooling costs. Your happy clients will thank you for years to come!

Don’t cut corners for long-term success

There’s a growing trend in modern homes, particularly in new estates, to apply only two coats of paint. While three coats will increase your client’s quote, the Master Painters Association advises three coats on all new surfaces as recommended by the paint manufacturer’s specifications and Australian Standards AS/NZ2311. Along with the appropriate prepping and priming, the application of a third coat will also allow a premium-grade paint to perform to its maximum in Australia’s harsh summers. By focusing on delivering a high-quality service you’ll build trust with your clients and even foster repeat business – so go on, apply that third coat!

Stay safe under the sun

Heat stroke, dehydration and sunburn won’t help you get the job done any faster or better. Apply a 50+ sunscreen regularly, even in cloudy weather, wear light protective clothing and sunglasses, and keep an insulated bottle nearby so you can drink plenty of fluids throughout the day. And remember to give yourself short breaks in shaded areas to cool down and reboot. For more tips on how to work safely under the sun, check out our ‘Guide to sun safety for tradies’. 

When you’re tackling exterior painting projects in the peak of summer, the right techniques, time-saving products and expert advice can give you top-notch results in every brush stroke – no matter what the thermometer says.

Want to nail your summer painting projects?

Contact your local Bunnings Trade team to find out more about our professional-grade painting solutions. Our team can offer technical advice on the best products to help you deliver that flawless paint finish you’re after.

Frequently Asked Questions

1. What temperature is best for exterior painting in hot weather?

The ideal temperature for exterior painting is below 35°C, as heat speeds up drying and can lead to blistering, peeling or visible brush marks. Use a weather app to plan work during cooler morning or late‑afternoon periods. 

2. How does humidity impact exterior painting?

Humidity slows paint drying and can trap moisture, causing stickiness, mould, bubbling and peeling. Aim for a humidity range of 40–70 per cent to ensure proper adhesion and a smooth finish. 

3. What’s the best way to stop paint drying too fast in summer?

To prevent rapid drying, paint in shaded areas, work ahead of the sun and break the project into smaller sections. Adding an acrylic paint conditioner can also extend open time and improve flow in hot, windy weather.

4. Can I use dark exterior paint colours in Australian summer conditions?

Dark colours absorb more heat and may deteriorate faster, causing blistering or chalking. If clients prefer darker tones, choose premium exterior paints with UV‑barrier technology to minimise heat‑related damage. 

5. Why do professionals recommend applying three coats of paint?

Three coats ensure better durability and help premium‑grade paints perform correctly, particularly in harsh summer conditions. It delivers a longer‑lasting finish and supports higher workmanship standards on new surfaces.