Up to 250 mm (9.8 inches) of rain and 130 km/h (80 mph) gales forecast for parts of New Zealand’s South Island

A front preceded by a strong, moist north to northwesterly flow is forecast to bring up to 250 mm (9.8 inches) of rain to parts of New Zealand’s South Island and severe wind gusts up to 130 km/h (81 mph) in exposed parts of the Canterbury High Country from Friday, July 3, to Saturday, July 4, 2026.

New Zealand’s MetService has issued Orange Heavy Rain Warnings for the ranges of Westland, Fiordland about and north of Doubtful Sound, and the headwaters of Canterbury and Otago lakes and rivers. An Orange Strong Wind Warning has also been issued for the Canterbury High Country. There remains a minimal chance of upgrading some of them to a Red Warning.

The front is forecast to approach New Zealand from the west and move east across the South Island on Saturday. MetService warned that streams and rivers could rise rapidly, with surface flooding, slips, and difficult driving conditions possible.

The ranges of Westland are forecast to receive 200 to 250 mm (7.9 to 9.8 inches) of rain between 03:00 and 23:00 NZST on Saturday. Peak rainfall rates of 20 to 30 mm/h (0.8 to 1.2 inches/h) are possible, with thunderstorms also possible.

The headwaters of Canterbury lakes and rivers south of Arthur’s Pass are forecast to receive 160 to 210 mm (6.3 to 8.3 inches) near the Main Divide and 110 to 160 mm (4.3 to 6.3 inches) within 20 km (12 miles) farther east. The warning is valid from 06:00 to 21:00 NZST on Saturday. Peak rainfall rates of 20 to 30 mm/h (0.8 to 1.2 inches/h) are possible near the Main Divide, with thunderstorms also possible. The freezing level is forecast near 2 200 m (7 200 feet).

For the headwaters of Otago lakes and rivers, MetService forecasts 150 to 200 mm (5.9 to 7.9 inches) near the Main Divide and 100 to 150 mm (3.9 to 5.9 inches) within 20 km (12 miles) farther east. The warning is valid from 01:00 to 16:00 NZST on Saturday. Peak rainfall rates of 20 to 30 mm/h (0.8 to 1.2 inches/h) are possible near the Main Divide, with thunderstorms also possible. The freezing level is forecast to lower from about 2 500 m (8 200 feet) to 1 800 m (5 900 feet) during the day.

Fiordland about and north of Doubtful Sound is forecast to receive 120 to 180 mm (4.7 to 7.1 inches) of additional rain between 19:00 NZST Friday and 13:00 NZST Saturday. MetService said this rainfall will fall on top of what has already been received. Peak rainfall rates of 20 to 30 mm/h (0.8 to 1.2 inches/h) are possible on Saturday, with thunderstorms also possible.

Severe northwesterly gales are forecast in exposed parts of the Canterbury High Country from 09:00 to 21:00 NZST Saturday, with gusts up to 130 km/h (80 mph). MetService said the winds could damage trees, power lines, and unsecured structures, while making driving difficult, particularly for high-sided vehicles and motorcycles.

A Heavy Rain Watch remains in place for Fiordland south of Doubtful Sound from 19:00 NZST Friday to 11:00 NZST Saturday. Periods of heavy rain are forecast, with rainfall totals potentially approaching warning criteria.

Residents under orange warnings were advised to clear drains and gutters to prepare for heavy rain, avoid low-lying areas, and drive cautiously. In regions under wind warnings, residents are advised to prepare their properties by securing items that can be picked up by strong winds and to drive cautiously.

References:

¹ Heavy rain and severe gales for parts of the South Island – MetService – Accessed 08:15 UTC on July 3, 2026

Featured image: Satellite image of New Zealand acquired at 01:50 UTC on July 3, 2026. Credit: JMA/Himawari-9, Zoom Earth, The Watchers