GUIDE
Hong Kong's Pest Calendar: Every Pest Has a Season — Get Ahead of It
Quick answer
Hong Kong's pest problems broadly track the weather: the spring damp period (roughly February to April) is peak season for booklice and mould; termites generally swarm from April to July; mosquitoes are active roughly March to November, with May to September the busiest stretch; wasp nests get largest and most aggressive roughly August to October; bed bugs are a year-round risk, with luggage-related infestations rising during heavy-travel periods; and cockroaches, rodents and ants are a constant, year-round fight. The best time to get ahead of almost anything is before its peak — the month-by-month breakdown below covers each one.
The year at a glance
- Jan — prep month: check dehumidifiers and window seals before the spring damp arrives; check luggage after year-end travel.Booklice handbook
- Feb–Mar — booklice, mould (spring damp): humidity monitor, dehumidify, clean mould.Booklice handbook,
- Humidity tracker
- Apr–May — termite swarming begins + rising mosquito activity: lights off, windows closed against swarming termites; clear standing water.Termite signs,
- Mosquito index tracker
- Jun–Jul — peak mosquito season, termite swarming tapers off, cockroaches active: weekly check of standing-water sources; bait deployment.Mosquito control,
- Cockroach DIY vs professional
- Aug–Sep — wasp nests at their largest and most aggressive + mosquitoes still active: check eaves and balconies; deal with small nests early.Wasp nest removal
- Oct–Nov — year-end travel season: bed bugs travel home in luggage, mosquito season tapering. Build the luggage-check habit; hot-wash on return from trips.How bed bugs get in
- Dec — year-end clean-up: seal gaps, fix window seals, clear clutter that hides pests.Rats entering the home
- Year-round — cockroaches, rodents, ants, fleas: keep food sealed, drain covers on, take out rubbish daily (each pest hub page).
Months are a general pattern that shifts year to year with the weather — for current mosquito conditions, see our monthly-updated mosquito index tracker; for humidity, see the humidity tracker.
Why "get ahead of it" matters
The cost of dealing with any pest problem tracks almost exactly with how late you catch it: a small wasp nest costs less than a large one; controlling humidity before the spring damp costs less than removing mould and booklice afterwards; and doing the right three things on a termite swarming night — lights off, windows closed, checking the next morning — can save you a full inspection bill. The point of a calendar isn't to alarm you; it's to give you one small prevention task, two to four weeks ahead of each peak.
Can't remember what to check each month? Save this page, or just WhatsApp us and ask what matters right now
Frequently asked questions
Is this calendar the same every year?
The broad pattern holds year to year, but exact months shift with the weather — for something like when mosquito season actually starts, FEHD's index is the most reliable reference, and our tracker updates it monthly.
Which month should I book a full home check?
Two points work best: just before the spring damp (late January, ahead of humidity and booklice) and just before summer (April, ahead of mosquitoes and termites). Year-end clean-up, when you're sealing gaps anyway, makes a good third.
I've only just noticed a pest problem — is it too late?
It's not "too late", it's "cheapest right now" — the longer it sits, the more it costs to deal with. Photograph what you're seeing and WhatsApp us; we'll tell you the same day whether it needs treating.