Severe weather struck much of New Zealand on Thursday, May 1, as heavy rains triggered floods over parts of the South Island, prompting a State of Emergency. Wellington and much of the North Island experienced strong winds and heavy rain, leading to a Red Alert issued by MetService.

Heavy rainfall began over New Zealand on Wednesday, April 30, and continued through Thursday, May 1. The Canterbury region in the South Island received between 100 and 180 mm (3.9 to 7.1 inches) of rain by midday Thursday, with some areas recording more than twice the average monthly rainfall within 24 hours.

The Christchurch airport reported 80.2 mm (3.1 inches) of rainfall in 24 hours ending at 09:00 local time (LT) on Thursday, the fourth-wettest day on record for the region since records began in 1943. The average rainfall for May at Christchurch Airport is 58.4 mm (2.2 inches).

Christchurch flooding on May 1, 2025Flooding in Christchurch on May 1, 2025. Image credit: Christchurch City Council

Comparable rainfall totals were reported across the ranges of the Tairāwhiti Gisborne Region in the North Island since Wednesday morning.

The heavy rains triggered severe flooding as rivers overflowed across the affected regions. Although no injuries or fatalities were reported, the floods caused significant traffic disruptions and widespread damage across the region.

The flooding closed multiple routes in the affected districts, including Christchurch and Selwyn, while multiple landslides were reported across the affected regions.

Flooding in Christchurch on May 1, 2025Flooding in Christchurch on May 1, 2025Flooding in Christchurch on May 1, 2025. Image credit: Christchurch City Council

The central Selwyn District in the South Island issued an emergency warning earlier on Thursday as the Selwyn River exceeded flood levels in the evening.

District Mayor Sam Broughton stated that flooding risks had developed across Selwyn, particularly in low-lying areas, and urged residents in high-risk zones to evacuate on Thursday.

Flooding Selwyn on May 1, 2025Flooding Selwyn on May 1, 2025Flooding Selwyn on May 1, 2025. Image credit: Selwyn District Council

Although the North Island also experienced heavy rainfall, strong winds were the primary concern. Wind gusts at Wellington Airport reached 118 km/h (74 mph). Local media reported that average wind speeds in Wellington peaked at 87 km/h (54 mph), the highest since 2013, while gusts at Baring Head south of the capital reached 160 km/h (99 mph).

Mt. Kaukau reported a gust of 141 km/h (88 mph), while Kelburn saw a gust of 117 km/h (73 mph).

Severe weather conditions caused multiple flight delays and cancellations at Wellington Airport. Schools and other institutions across both islands were closed until Friday, when MetService lifted weather warnings.

Ferry services were also closed as the strong winds brought rough seas and high waves in coastal areas.