Climate of New Zealand facts for kids

Climate types in New Zealand

New Zealand has a diverse climate because its landscape changes a lot. Most of the country is in a temperate zone. This means it has four clear seasons: mild winters and cool summers. The huge Pacific Ocean and New Zealand's position on the globe are the main reasons for its climate. However, big mountain ranges can make the weather very different in places that are close to each other. For example, the West Coast of the South Island is very wet. But Central Otago is almost like a desert. And Northland in the north has a warm, subtropical climate.

Understanding New Zealand's Weather

The Meteorological Service of New Zealand Limited (MetService) is a special company. It gives out weather forecasts and official warnings. This helps people know what weather to expect.

How Much Rain Falls?

Most cities in New Zealand get a good amount of rain each year. For example, Christchurch gets about 618 mm (24 inches). Whangārei gets more, around 1317 mm (52 inches). In most parts of the country, especially the South Island, rain falls pretty evenly all year.

However, some areas like Auckland, Christchurch, and Wellington get more rain in winter. Places closer to the southwest, like Invercargill and Milford Sound, get more rain in summer and autumn.

The amount of rain a place gets really depends on its mountains and hills. The Southern Alps and other ranges can cause huge differences in rainfall. This can happen even in places just a few kilometres apart. For instance, Milford Sound gets over 6,700 mm (264 inches) of rain each year. But only about 100 km (62 miles) away, Alexandra in Central Otago gets only a little over 300 mm (12 inches) annually.

This happens because air full of water vapour from the ocean is pushed from the west. When this humid air hits the Southern Alps, it's forced upwards. As it goes higher, the air cools, and the water turns into rain or snow. This is called orographic rain. It explains why the west side of the South Island is so wet and the east side is so dry. The drier, warm wind that then blows down the eastern side of the mountains is called a föhn wind. It creates a special cloud formation called the Nor'west arch, which you can often see in Canterbury and parts of Otago.

Tornadoes in New Zealand

Each year, New Zealand usually has about 7 to 10 damaging tornadoes. They mostly happen along the west coast of both islands. Tornadoes in New Zealand often form from strong storm lines that come before cold fronts. These storms can create spinning air columns that lead to tornadoes.

Most tornadoes in New Zealand are short, narrow, and not very strong. However, the National Institute of Water and Atmospheric Research (NIWA) studied the 1948 Frankton tornado. They found it was an EF3 on the Enhanced Fujita scale, making it the strongest known tornado in New Zealand's history. This tornado also caused a lot of damage, affecting 200 buildings. Sadly, it also caused three deaths, which is rare for tornadoes in the country.

Snowfall in New Zealand

The Midland Line covered in heavy snow

Snow falls in the South Island and in higher areas of the North Island. It is very rare for snow to fall at sea level in the North Island. Snow is more common inland on both main islands. However, snow does reach sea level in the central and southern South Island about once or twice a year.

Temperatures Across the Country

Because New Zealand is surrounded by the ocean, coastal temperatures don't get too extreme. The biggest temperature differences are found inland. This is especially true in Central Otago and the Mackenzie Basin in Canterbury. These areas are drier and less affected by the ocean. They can have summer temperatures in the low 30s °C (high 80s/low 90s °F). In winter, they can get snow and very cold frosts.

Average Yearly Temperatures

Average yearly temperatures range from about 10 °C (50 °F) in the south to 16 °C (61 °F) in the north. The coldest month is usually July, and the warmest is usually January or February. Generally, there isn't a huge difference between summer and winter temperatures. For example, Auckland only has a 9 °C (16 °F) difference between its average mid-winter high and average mid-summer high.

Temperatures also drop by about 0.7 °C (1.3 °F) for every 100 m (300 ft) you go up in altitude.

Northern cities like Auckland, Whangārei, and Tauranga have average yearly high temperatures between 19–20 °C (66–68 °F). Their average yearly low temperatures are around 11–12 °C (52–54 °F). Cities on the east of the North Island, such as Gisborne, Napier, and Hastings, also have similar average yearly highs. But their average yearly lows are a bit cooler, around 9–10 °C (48–50 °F).

The two largest cities in the South Island, Christchurch and Dunedin, have average yearly highs of 17.3 °C (63.1 °F) and 14.6 °C (58.3 °F). Their average yearly lows are 7.3 °C (45.1 °F) and 7.6 °C (45.7 °F) respectively.

Summer Temperatures

Daily high temperatures in summer are usually in the mid to low 20s (°C) across most of the country. They are higher in the northern, eastern, and inland parts of New Zealand. Hastings is the warmest city on average, with 25.5 °C (77.9 °F). Gisborne is next with 24.9 °C (76.8 °F), followed by Napier with 24.5 °C (76.1 °F).

Eastern parts of the South Island can get very hot due to the norwester wind (a type of Fohn wind). This wind can push temperatures into the high 30s and even low 40s (°C). Rangiora in Canterbury holds the record for the highest temperature ever recorded: 42.4 °C (108.3 °F) in 1973. Christchurch reached 41.6 °C (106.9 °F) that same year. More recently, Timaru reached 41.3 °C (106.3 °F) in 2011. Because of these winds, cooler South Island cities like Dunedin, Christchurch, and Invercargill have higher all-time record temperatures than some northern cities like Wellington and Auckland.

Winter Temperatures

Snowfall in Dunedin, Otago during August 2011

Winter temperatures in New Zealand are quite mild compared to other places at the same latitude. The main exceptions are Central Otago and the Mackenzie Basin. High temperatures are generally 10-15 °C (50-59 °F) in the North Island. They get cooler as you go further south or inland. The South Island is a bit colder, with high temperatures around 7-12 °C (45-54 °F), though sometimes lower. The lowest temperature ever recorded was -25.6 °C (-14.1 °F) in Ranfurly, Otago, in 1903. More recently, -21.6 °C (-6.9 °F) was recorded in nearby Ophir in 1995.

Major Weather Events

New Zealand has experienced several powerful weather events throughout its history.

• July 1863: A series of bad weather events hit Central Otago. Floods, snowstorms, and blizzards caused many gold miners to lose their lives. At least 40 people died during the July rains, and more than 11 in the August snows.
• 1–6 February 1868: The Great storm of 1868 was a very strong storm that swept across New Zealand. It sank 12 ships and caused widespread flooding. About 40 lives were lost, and the damage was estimated to be very costly. This storm is now thought to have been a former tropical cyclone.
• 16 April 1897: A severe storm hit the lower to central North Island. It caused the ship Zuleika to run aground, leading to 12 deaths. There was also severe flooding, which caused another 12 deaths in Clive. This storm might also have been a former tropical cyclone.
• 2 February 1936: The Cyclone of 1936 was considered the worst storm of the 20th century in New Zealand.
• 10 April 1968:
  

  The path of Cyclone Giselle
  Cyclone Giselle brought very strong winds, with gusts up to 270 km/h (168 mph) near Wellington. This happened after it crashed into a storm coming from Antarctica. Giselle caused the interisland ferry TEV Wahine to sink, and 53 people died. The total damage from the storm was estimated at $14 million.
• 20 December 1976: Heavy rain caused widespread flooding and landslides in Wellington City and Hutt Valley. The Hutt River overflowed its banks. Workers in Petone had to climb onto factory roofs. Train services between Wellington and the Hutt Valley were stopped, leaving thousands of commuters stranded. Landslides destroyed houses, and a boy died when a wall collapsed in Crofton Downs. More than 350 mm (14 inches) of rain fell in just 24 hours.
• 6–10 March 1988: New Zealand is hit by a tropical cyclone about once every eight to nine years. Cyclone Bola was one of the most expensive cyclones in New Zealand's history. It caused severe damage as it passed near the country.
• 4 October 1997: More than 60 homes were flooded, and people in Lower Hutt riverside areas had to leave their homes during heavy rain. Two people died. Landslides closed some roads in Wellington and parts of State Highway 1.
• 26 June 1998: A severe thunderstorm affected Karori and Kelburn. The rain broke all previous records, falling at an extremely fast rate.
• 13–27 October 1998: Strong northwesterly winds blew across the lower North Island. On October 18, gusts of 183 km/h (114 mph) were recorded at Castlepoint. The winds were strongest on the next two days, with a gust of 215 km/h (134 mph) recorded on a farm in Wairarapa. A truck was overturned, ships were pulled from their moorings in Wellington, and some houses lost their roofs.
• 10 January 2002: Thunderstorms over Wellington brought very heavy rainfall, about 40 mm (1.6 inches) in 30 minutes. This caused flash floods in the city centre. Similar storms with hail and flooding also happened in other parts of the North Island and in the Buller and Nelson regions.
• 14–16 February 2004: The Valentine's Day storms left hundreds of people without homes. Silt and floodwaters covered large areas of farmland. Many rivers overflowed, bridges were damaged, and farm animals were swept away by floods. A state of emergency was declared in Whanganui, Manawatu, and Rangitikei. About 500 people in Lower Hutt had to leave their homes because of the floods. Many commuters couldn't get into Wellington. The storm also brought strong southerly winds, with gusts of 230 km/h (143 mph) in the Tararua Range, and waves of 11 m (36 ft) in Cook Strait.
• 25 July and 14 August 2011: The first severe winter storm brought the coldest winter weather in fifteen years. In August, snow fell consistently down to sea level in Wellington for the first time since 1976. Snowflakes even fell for a short time in Auckland for the first time in 80 years.
• 20–21 June 2013: This large storm first brought heavy snowfall to the South Island on June 18 and 19. Late on June 20, the storm moved northeast to the North Island, bringing very strong winds until June 23. Schools were closed on the shortest day (June 21) because of widespread damage.
• 12-16 February 2023: The remains of Cyclone Gabrielle passed over the North Island. It brought heavy rain and strong winds, causing serious flooding in many areas. Sadly, 11 people lost their lives, and the damage cost $13.5 billion. This made Gabrielle the deadliest cyclone since Giselle and the most expensive cyclone ever recorded in New Zealand.

Climate Facts and Figures

Climate by Area

Weather Records

Annual Extreme Weather

New Zealand's Climate History

Scientists started collecting detailed weather information for New Zealand in the late 1800s. However, European explorers had already noticed climate signs like glaciers earlier that century. Studying New Zealand's past climate is a newer field, and it's still ongoing.

Scientists have learned that New Zealand did experience a cooler period, similar to the Little Ice Age (LIA) in the Northern Hemisphere. This cooler time in New Zealand started around 1450 and lasted until 1850. During this period, temperatures were about 1.5-2.0 degrees Celsius lower than they are today.

Since 2000, studies have shown that glaciers are excellent indicators of temperatures, especially in summer. Evidence from glaciers matches what scientists found in tree rings and samples from ice cores and ocean sediments. These samples show different types of tiny living things (some like warm, some like cool) and past levels of carbon dioxide.

Research has found that New Zealand's climate was more affected by warm air from the tropics during warm periods. It was more affected by cold air from the poles during cool periods. Recent studies from Victoria University (2010) showed that coastal Otago and Southland were most affected. The main reason for temperature changes there was how warm the sea south of New Zealand was during the Medieval Warm Period (MWP). From about 1350, this region was noticeably warmer. But then it cooled down quite quickly from 1450. This cooling might have had a big impact on the people living in those areas. Historical records suggest that from 1450, the people of New Zealand went through big cultural changes. These changes might be linked to the climate cooling and major shifts in their food sources.

Climate Change in New Zealand