When is the best time of year to paint a house exterior around Melbourne?

What do the weather records say for the Peninsula?

The Bureau of Meteorology publishes long-term averages for weather stations around the Peninsula. At Cerberus, near Crib Point on Western Port, the average number of rain days (1 mm or more) is lowest from January to March, at about 4 to 6 days a month, and highest from May to October, at about 10 to 12 days a month.

Temperatures follow the same pattern. Cerberus averages daytime highs of about 23 to 25°C from December to March and about 14 to 15°C from June to August, with average overnight lows in winter around 6 to 7°C. Conditions vary across the Peninsula, from the bay side to Western Port and the hinterland, but the seasonal pattern is the same.

• December to March: fewest rain days, warm days, longest daylight. Watch for very hot days.
• October, November and April: often good, with more changeable weeks.
• May to September: cooler, damper and shorter days, with more dew and slower drying.

What temperature is too cold to paint outside?

It depends on the product, so the label or data sheet is the final word. Dulux's Weathershield range can be applied when temperatures are above 5°C during application and drying, while Dulux's Professional Exterior Low Sheen says not to paint below 10°C, including if the surface could drop below 10°C while drying. Other brands give their own ranges, so never assume one product's limit applies to another.

The catch in cooler months is the surface temperature, not the forecast high. Timber and render in shade, or first thing in the morning, can sit well below the air temperature, and dew can form on them late in the afternoon. That's why winter painting days are shorter: start once surfaces have warmed and dried, and finish early enough for the paint to dry before the evening dew.

Can it be too hot to paint?

Yes. Haymes warns that paint applied above 32°C can bubble, and advises against painting in direct sunlight. On a hot day a wall in full sun can be much hotter than the air, and the paint dries too fast to flow out and bond properly.

On summer jobs the usual approach is to follow the shade around the house: east walls in the afternoon, west walls in the morning, and nothing in full midday sun on the hottest days. Dulux's Weathershield datasheet also suggests hosing surfaces to cool them and painting the shady side during the hottest part of the day.

How much does rain and dew matter?

A lot. Haymes says not to paint if rain or dew is expected within 24 hours. Dulux notes that rain or overnight dew while the coating is drying can damage it. Some specialist coatings have stricter limits: the datasheet for Dulux Acratex AcraShield Advance says not to apply above 85 per cent relative humidity or within 3°C of the dew point, and to protect it from dew, rain and frost for 48 hours.

Melbourne weather is famous for changing its mind, so a dry morning isn't a guarantee. A careful painter checks the forecast for the whole drying period, not just the hours they'll be on the ladder. Paint that's hit by rain before it has dried can streak, wash off, or leave a patchy, weakened finish that fails sooner.

Does it matter when you book, not just when you paint?

It does. The warmer, drier months are also when most people want their outside painted, so good painters' calendars tend to fill up well ahead. If you'd like the job done over summer, it makes sense to get quotes in late winter or early spring.

Autumn can be a good compromise. The worst of the heat has gone, many days are still dry and mild, and there's often more flexibility on start dates. The trade-off is shorter days and the first cold, dewy mornings from about April.

What about interior painting?

Inside work is far less tied to the seasons, which is why winter is a sensible time to get interior repaints done. The paint still needs reasonable temperatures and airflow to dry, so heaters and open windows help on cold, damp days. Bathrooms are the exception worth planning for: see our guide to mould on bathroom ceilings.

What happens if the weather turns during a job?

On any outside job some days will be lost to rain, wind or dew, whatever the season. What matters is that it's planned for. Ask each painter how they handle weather delays and whether the quote allows for them.

When we paint a house exterior, you get a planned schedule before we start, and if the weather moves the dates, we give you a heads-up rather than pushing on in bad conditions. If you're thinking about an exterior repaint, we can talk through timing when we come to quote.

Quick questions

Sources

What this guide relies on. Product advice changes, so check the maker's current instructions for the exact paint you're using.

1. Climate statistics for Cerberus (086361) — Bureau of Meteorology
2. Weathershield Low Sheen: application conditions — Dulux
3. Professional Exterior Low Sheen — Dulux
4. Top 10 outdoor painting tips — Haymes Paint
5. Acratex AcraShield Advance datasheet — Dulux Acratex