Five wet months, February to June
At the Sydney Observatory Hill station the averages come to 1,149 mm of rain a year. February and June stand out as the two wettest months, with March, April and May between them. From July the months grow drier until September, the driest, before the rain picks up again into November.
January and February share the warmest nights, January's averaging 20.0°C, and nights stay warm into March. July has the coldest nights, June and July share the coolest days, July's averaging 17.9°C, and from August to January no month's days are cooler than the month before. December and March share an average maximum of 25.7°C.
Autumn among the wet months
Autumn at Observatory Hill falls wholly within the wet months from February to June, and its days ease from March's warmth to 20.9°C in May. Spring opens on September's light rain, and the rain returns slowly through October and November while the days move towards summer warmth.
Pests and weather, from public sources
Termites
New colonies begin when winged termites leave the nest in a colonising flight. The Australian Museum says these flights happen in warm, humid weather, mostly in spring and autumn.
Australian MuseumCockroaches
The Better Health Channel says cockroaches do best where conditions are warm, humid and unhygienic.
Better Health Channel (Victorian Government)Mosquitoes
“Mosquitoes need water to breed, and some mosquitoes can breed in very small amounts of water.”
NSW HealthTicks
Ticks can be found in any month. The Australian Government’s health advice puts the usual tick season at July to December, and says it differs from place to place.
Australian Centre for Disease ControlWho licenses pest work in New South Wales
In New South Wales, the law requires anyone doing prescribed pesticide work to hold a licence, and pest management technician licences come from the NSW Environment Protection Authority (EPA). NSW EPA
The EPA also accepts some similar licences issued in other states and territories, though not those issued in Queensland. NSW EPA
Every pesticide licence the EPA issues goes on a public register. NSW EPA
The EPA’s advice is to ask to see a pest controller’s licence before agreeing to any pest control work. NSW EPA
How to check a pest controller’s licence, NSW EPA