Mosquito season in Australia: when to install fly screens
Camille VidalThe best time to fit fly screens is not the height of summer: it is just before the season, in September, when the first warm days wake the mozzies. A made-to-measure screen takes 6 to 9 business days to make: order in September and you are sleeping soundly by November; order mid-invasion and you lose a week or two of good nights waiting for the parcel. Down here the calendar is the mirror of Europe's: our spring is called October.
Here is what a mosquito season really looks like in the southern hemisphere, and the right moment to act depending on your situation.
The real calendar of a mosquito season
Mosquitoes do not read the calendar, they read the thermometer. Once nights settle around ten degrees and above, the first species come out of their winter pause. Activity builds through spring, peaks over the warm months, especially after rain, then fades with the first cool autumn nights. Two moments catch everyone out: the very start of the season, because nobody quite believes it yet, and the weeks after a summer downpour, when every saucer under a pot plant becomes a nursery.
In practice that means a season running roughly from October to April, peaking over the summer months. In other words: if you wait until you are bitten to act, the mozzies are already two to three weeks ahead of you.
Why equip before the peak (and not during)
The maths is simple. A made-to-measure fly screen takes 6 to 9 business days to make, plus delivery: ordered in September, it is up when the first wave arrives with the October warm-up; ordered mid-season, it costs you a week or two of ruined nights, often just after the rains that send mozzie numbers soaring. And in parts of Australia this is about more than comfort: health authorities remind us each wet season that some mosquitoes here can carry Ross River virus.
Equipping early also means measuring and fitting calmly: about ten minutes per opening, no pressure, at a time you choose. Our measuring guide walks you through it step by step, opening by opening.
The right moment for your situation
Moving in or renovating? Take the opportunity to measure every opening in one go: equipping the whole house in a single order saves you chasing fly screens room by room once summer arrives, and quantity discounts work in your favour. A holiday home deserves the same reflex: equip it when you open it up in spring, not the day before the August holidays.
Renting? The no-drill version goes up and comes down without leaving a trace, which makes it worthwhile even for a single season. Already equipped? Spring is the time to check the mesh and fixings: our guide to maintaining and repairing your fly screen covers it all in ten minutes. A tired adhesive strip or a small snag spotted in April gets fixed calmly; discovered in July, it has to be endured.
When autumn comes: remove, leave in place, or plan for next year
An E-glass fibreglass mesh handles the seasons and lasts 8 to 20 years: leaving it in place over winter does not damage it. If you prefer a bare window in the off season, the magnetic fixings let you take the mesh down in seconds and put it back up in spring, without re-sticking anything. Nothing stops you from turning it into a seasonal ritual, down in autumn and back up in spring: the mesh spends winter folded in a cupboard and comes out as good as new.
And winter has a hidden virtue: June to August is the perfect window to measure and order calmly, with no urgency and no mosquito on the ceiling. The truly organised fit their screens in August and never hear the first buzz of October.
Northern hemisphere: same logic, six months earlier
In Europe and North America the logic is identical but the calendar flips: the season runs roughly from mid-spring to early autumn, peaking in July and August.
Same product, same anticipation, opposite dates: while windows are closing in Sydney or Auckland, they are opening in Paris.
Build my made-to-measure fly screen
Frequently asked questions
When should you install fly screens?
Before the season: order in September so everything is up before the October warm-up. Fitting takes about ten minutes per opening, with no tools and no drilling.
Should you remove the fly screen in winter?
It is not necessary: fibreglass handles the seasons without damage. If you prefer, the magnetic fixings come down and go back up in seconds.
Do mosquitoes really disappear in winter?
Activity drops sharply with the cold, but some species overwinter in shelter, sometimes in cellars and garages, and an early mild spell can wake them up. All the more reason to be equipped before everyone else.
How far ahead of the season should you order?
Allow 6 to 9 business days of making for made to measure, plus delivery. Ordering in September, two to three weeks before the first real heat, leaves all the margin you need.
Is a fly screen useful outside mosquito season?
Yes: it also stops flies, limits the leaves and dust that come in when you air the house for a long time, and lets you sleep with the windows open from the first fine days.
If you are equipping a home in Australia, the calendar is only half the question. The other half is which opening you start with, and that depends a great deal on where you live: a Queensland patio that stays open from October, a Melbourne sliding door that only matters for eight weeks, a Top End wet season that changes the maths entirely. We set out what works market by market on our page about fly screens in Australia.
When to fit, if you are in Australia
The northern hemisphere advice in this article inverts here, and it does not invert cleanly, because Australia does not have one season. It has at least two patterns and they call for different timing.
The southern pattern: Perth, Adelaide, Melbourne, Sydney
Numbers build from October, the difficult evenings run from December through January, and pressure eases through late February. The useful window for fitting is therefore September and early October, before the build rather than during it. Fitting in January works, but by then you are dealing with adults that have already emerged rather than preventing them, and you are doing it on the evenings you wanted to be using the deck.
The tropical pattern: Brisbane north, Darwin, the Kimberley
Here the calendar matters less than the rain. Numbers climb within a week or two of the first serious falls and stay high while the ground holds water, which can mean November through April. The build up, before the wet properly breaks, is often the worst of it because the humidity is already there. Fitting before the first rains is the equivalent of the southern September, and it is a much shorter window.
The one that catches people out
A warm, wet week out of season produces a wave about ten days later, whatever the month. Coastal areas near saltmarsh get the same effect from a big tide rather than from rain. If you have ever wondered why one October evening was unbearable and the next three were fine, that is usually what happened, and it is an argument for having the screens up early rather than reacting.
What to do at the end of the season
Take stock in late February or March rather than promising to remember. Check the mesh for stiffness from ultraviolet, which is what Australian summers do to screens, and check the fixing for anything the heat or the salt air has worked loose. Both are five minute jobs then and expensive discoveries in December.