A busy night for Wellington fire crews as strong winds bring down power lines and send trampolines flying

Northwesterly gales, with gusts of up to 120 kilometres per hour, are sweeping across the lower North Island.

Fire Shift Commander Belinda Beets says trampolines have needed rescuing, roofs have needed securing, and downed power lines have needed to be cleared from roads.

A railway barrier arm in Carterton has also been left bent by the wind.

And there's disruption on the water with Wellington harbour ferries running to a restricted timetable due to the wind.

Flights are unaffected at this stage.