Kitchen chimney exhaust vents and other wall or roof-mounted ventilation outlets deserve a check before the monsoon season arrives, since these openings, designed primarily for airflow rather than water resistance, can become an entry point for rain if their weatherproofing has degraded over time. External vent covers or flaps, which normally allow air out while preventing rain and pests from entering, can become stuck open due to grease buildup or general wear, and confirming these move freely and close properly when the exhaust fan is not running is a useful pre-monsoon check.
Sealant around the vent's wall or roof penetration point can crack or shrink over years of temperature cycling, creating a path for water to track along the ducting into the wall cavity or ceiling space during sustained heavy rain, even if the vent opening itself is otherwise functioning correctly. Ducting runs that pass through unheated or unconditioned spaces, such as an attic or a narrow service shaft, are worth checking for any signs of previous water staining, which would indicate an existing minor leak that heavier monsoon rainfall could worsen if left unaddressed.
Addressing these vent and ducting checks before the season begins is generally more straightforward than dealing with water damage discovered only after a heavy rain event has already occurred.