Wild winds were felt from Wellington to Invercargill today, with gusts blowing a trampoline through power lines in Christchurch.
Wellington, Christchurch, Dunedin and Invercargill all experienced wind gusts of 100km/h, with some exposed places gusting up to 120km/h, MetService said.
A severe weather warning was in place and would be reviewed tonight, meteorologist Emma Blades said.
"Heavy rain has fallen in the Tararuas this morning, with 100mm in six hours and torrential falls of 30mm per hour," she said.
A cool southwesterly flow will lower temperatures across the country, particularly in the south, this week.
Areas in Southland would struggle to reach 10C tomorrow, MetService said.
Showers are forecast for western parts of the country, including Auckland, on Monday and Tuesday.
While the South Island will feel the chilly weather brought in by the southwesterly flow, most parts of the North Island will remain in the high teens throughout the week, MetService said.
Warmer northwest winds will precede another front that will come onto the South Island on Wednesday, bringing the temperatures back up to the low 20s for most of the South Island.