Heavy swell warning: Kapiti to Cape Terawhiti
MetService has issued a Heavy Swell Warning for the Kapiti–Porirua Coast, stretching from Ōtaki to Cape Terawhiti. The warning runs for seven hours, from 2am to 9am on Thursday 18 September.
Northwest swells are expected to rise to 3–3.5 metres, with combined wave heights of 4–4.5 metres at their peak. The swell period is forecast at around 10 seconds, making for a powerful sea state. Wind waves of about 3 metres will add to the rough conditions.
The highest risk period aligns with the morning high tides:
- Makara Beach: 6:23am Thursday
- Ōtaki River Entrance: 7:16am Thursday
Conditions are expected to ease after mid-morning.
Strong winds for Wairarapa and Tararua
An Orange Strong Wind Warning is in force for Wairarapa and the Tararua District, covering the four-hour window from 8am to midday on Thursday.
MetService expects severe gale northwesterlies gusting up to 120 km/h in exposed areas. While the risk of an upgrade to a Red Warning is considered low, the impacts could still be significant.
Strong winds may damage trees, powerlines, and unsecured structures. Driving could be hazardous, especially for high-sided vehicles and motorcycles.
Waitemata Harbour / Harbour Bridge
SH1 AKL HBR BRIDGE – WIND WARNING
Strong wind gusts are expected to affect the Harbour Bridge today between 9am and 2pm. Speed restrictions and lane reductions are likely, while temporary full closures may be required.
Caution is advised. ^KF pic.twitter.com/2otSAh5XEl
— NZ Transport Agency – Auckland & Northland (@nztaaklnth) September 17, 2025
Advice for boaters and residents
Authorities recommend taking the following precautions:
- Secure property: Tie down or bring in items that could be picked up by strong winds.
- Plan boating trips carefully: Avoid launching during peak swell conditions.
- Drive with care: Expect sudden gusts on exposed roads and watch for debris.
- Stay informed: Check the latest MetService updates and forecasts.
- With both heavy seas and severe winds forecast, Thursday morning looks set to be challenging for coastal users across the lower North Island.
