Along with the blustery northwest gales, ramping up to storm force speeds of around 120 km/h in parts of Canterbury, Wellington and Wairarapa, torrential rain is set to drench western regions of both islands, with the South Island facing five days of non-stop rain.
The most rain is expected to fall in Fiordland and the West Coast with staggering levels of up to 240mm in the coming 21 hours.
MetService is warning the gales will be so strong they risk damaging trees, powerlines and sending unsecured structures flying.
Meanwhile, eastern regions of both islands will be basking in mild temperatures for the rest of the week.
Christchurch is set to hit 24C tomorrow, with temperatures only dipping down at the start of next week.
Napier is also set to bask in highs of 22C today and 23C on Thursday, while Gisborne enjoys similar temperate days for the rest of the working week.