Every year it follows the same pattern. The first warm weekend of June arrives, homeowners throw their windows open, and within a day or two the first flies are circling the kitchen and bumping against the bedroom ceiling at midnight. That's when we start receiving calls.
The honest answer to "when should I install fly screens?" is: before this happens. Specifically, April or May is the ideal window in the UK. Here's the reasoning behind that — and why winter installation is actually the smartest move of all.
Understanding the UK Insect Season
The UK's insect season is longer than most people realise. It broadly runs from April through to October, with activity peaking between late May and September. Different species peak at different times:
- April–May: Flying ants begin to emerge; early midges are active in the evenings
- June–July: Housefly activity increases significantly; bluebottles peak; mosquitoes become active near water
- August–September: Wasps reach maximum colony size and become aggressive; late-season midges are at their worst
- October: Activity tails off, though cluster flies (which overwinter in roof spaces) are a distinct nuisance in September and October
The upshot is that if you wait until flies are already a problem to think about screens, you've already lost several weeks of the most pleasant period for having windows open.
Why Spring Is the Ideal Time to Install
Installing in April or early May means your screens are in place before the main insect season begins. You get the full benefit across the whole summer rather than catching the back half of it. There are also practical advantages:
- Shorter lead times: Demand for fly screen installation increases sharply from late May onwards. Ordering in April typically means a shorter wait — often 5–7 working days from survey to install, compared to 2–3 weeks during peak summer.
- Better availability for surveys: Morning and late-afternoon survey slots are easier to secure in spring than in summer, which means less disruption to your day.
- Time to address any adjustments: If anything needs minor tweaking after installation (a mesh tension, a frame alignment), you have time to sort it before summer without any period of protection lost.
The Case for Winter Installation
If you want the best combination of lead time, availability, and price — winter is actually the optimal time. Between November and February, demand for fly screens is at its lowest. That means:
- Survey appointments are available within days rather than weeks
- Installation can often happen within 5 working days of your survey
- You're well ahead of any spring or summer backlog
- Some installers offer off-season discounts to maintain workflow through the quieter months
Fly screens installed in January are no different from screens installed in May — they sit in the frame and do nothing until you open the window. But by the time you're opening windows regularly in April, they're already there and working.
Practical tip: If you've just had new windows, doors, or bi-fold doors installed in autumn or winter, that's an excellent time to get fly screens measured and fitted simultaneously. The measurements are fresh, the frames are clean, and there's no rush — you're setting up the house properly from the outset rather than retrofitting in a hurry.
What to Expect: Survey to Installation
The process for getting fly screens fitted in Surrey is straightforward. Here's what a typical timeline looks like if you book in spring:
Initial contact and phone consultation
We discuss your openings, the types of screen likely to suit, and book a free survey. This usually takes 10–15 minutes and can happen same day.
Free survey (typically within 3–5 working days in spring)
We visit the property, take precise measurements of each opening, advise on the most appropriate screen type for each, and provide a fixed written quote — usually on the same day or the following morning.
Manufacturing (5–10 working days)
All screens are made to measure. Standard window screens typically take 5–7 working days; bi-fold and retractable systems can take 7–10 days. Rush options are sometimes available.
Installation (half a day for most homes)
Our installer arrives with all the made-to-measure screens and fits everything in a single visit. Most residential jobs — 3 to 8 openings — are complete within half a day. We leave the site clean and walk you through each screen before we leave.
The Bottom Line
The best time to install fly screens in Surrey is before you need them. If you're reading this in spring, you're in the ideal window — enquire now and you'll be protected for the whole summer season. If it's already mid-summer, we can still usually fit you in within a couple of weeks, and you'll protect the remainder of the season. If it's autumn or winter, you're in an enviable position: shortest lead times, best availability, and screens in place well before insects return.
Either way, the worst time is the one we hear most often: a hot Friday in July when the windows are open and the flies are already in. Don't be that person.