 Chatham Island (left) from space | |
 Map showing location of Chatham Island | |
| Geography | |
| Coordinates | 43°54′S176°29′W / 43.900°S 176.483°W /-43.900; -176.483 |
| Archipelago | Chatham Islands |
| Area | 920 km2 (360 sq mi) |
| Administration | |
| Demographics | |
| Population | 660 (2022) |
| Ethnic groups | Moriori,Māori |
Chatham Island (/ˈtʃætəm/CHAT-əm) (Moriori:Rēkohu,lit. 'Misty Sun';Māori:Wharekauri) is the largest island of theChatham Islands group, in the south Pacific Ocean off the eastern coast ofNew Zealand'sSouth Island. It is said to be "halfway between theequator and the pole, and right on theInternational Date Line", although that point is 173 miles[clarification needed] WSW of the island's westernmost point. The island is calledRekohu ("misty skies") inMoriori, andWharekauri inMāori.[1]
The island was named after thesurvey shipHMSChatham which was the first European ship to locate the island in 1791.[2] It covers an area of 920 km2 (355 sq mi).[3]Chatham Island lies 650 km (404 mi) south-east ofCape Turnagain, the nearest point of mainland New Zealand to the island.
The geography of the roughly T-shaped island is dominated by three features: two bays and a lagoon. More than half of the west coast of Chatham is taken up by the deep indentation of Petre Bay. The island's main settlement ofWaitangi is located in a small indentation inPetre Bay's southern coast. Other significant settlements areKaingaroa on the northeast promontory, andOwenga on the south side of Hanson Bay.
On the east coast is the even largerHanson Bay, which stretches for the entire length of the island (35 kilometres (22 mi)).[5]
Much of the area between the bays is taken up by the largeTe Whanga Lagoon, which drains to the sea to the east, into the southern half of Hanson Bay. This lagoon covers about 160 square kilometres (62 sq mi),[6] and drains several small rivers that rise in the hills at the south end of the island. The next largest lakes areRangitahi andHuro, respectively northeast and southwest of Te Whanga.[7] The central and north part of Chatham Island are mostly flat, with altitudes ranging from a few metres on the northeast and centre to 50 m on the northwest, but with a few scattered hillocks.[7] The south part is higher, generally sloping down towards north and west; about half of it is over 150 m above sea level. The south coast of the island is mostly cliffs 100 m high or more. The highest point of the island (299 m) lies close to its southernmost point.[7]
Chatham Island has anoceanic climate (Koppen:Cfb)[8] characterised by a narrow temperature range and relatively frequent rainfall. Their isolated position far from any sizeable landmass renders the record high temperature for the main settlement (Waitangi) just 23.8 °C (74.8 °F).[9] The climate is cool, wet and windy, with average high temperatures between 15 and 20 °C (59 and 68 °F) in summer, and between 5 and 10 °C (41 and 50 °F) in July (in the Southern Hemisphere winter). Snowfall is extremely rare, the fall recorded near sea level in July 2015 marking the first such reading for several decades.[10] Under theTrewartha climate classification, Chatham Island has ahumid subtropical climate (Cf) for the lack of cold weather during the winter and a daily mean temperature above 10 °C (50 °F) for eight months or more.
| Climate data for Chatham Islands (1991–2020) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Mean daily maximum °C (°F) | 19.2 (66.6) | 19.4 (66.9) | 18.2 (64.8) | 16.1 (61.0) | 14.0 (57.2) | 12.0 (53.6) | 11.3 (52.3) | 12.0 (53.6) | 13.2 (55.8) | 14.5 (58.1) | 16.0 (60.8) | 17.8 (64.0) | 15.3 (59.5) |
| Daily mean °C (°F) | 15.7 (60.3) | 16.1 (61.0) | 15.0 (59.0) | 13.1 (55.6) | 11.1 (52.0) | 9.3 (48.7) | 8.4 (47.1) | 9.0 (48.2) | 10.1 (50.2) | 11.1 (52.0) | 12.5 (54.5) | 14.4 (57.9) | 12.2 (54.0) |
| Mean daily minimum °C (°F) | 12.1 (53.8) | 12.7 (54.9) | 11.8 (53.2) | 10.1 (50.2) | 8.1 (46.6) | 6.5 (43.7) | 5.6 (42.1) | 6.1 (43.0) | 6.9 (44.4) | 7.7 (45.9) | 8.9 (48.0) | 11.0 (51.8) | 9.0 (48.2) |
| Average rainfall mm (inches) | 49.2 (1.94) | 64.0 (2.52) | 75.7 (2.98) | 79.0 (3.11) | 88.3 (3.48) | 93.7 (3.69) | 72.3 (2.85) | 71.0 (2.80) | 71.3 (2.81) | 56.2 (2.21) | 53.5 (2.11) | 62.9 (2.48) | 837.1 (32.98) |
| Average rainy days(≥ 1.0 mm) | 6.8 | 7.0 | 8.6 | 11.7 | 14.4 | 15.4 | 15.3 | 12.8 | 12.0 | 10.7 | 8.4 | 10.1 | 133.2 |
| Averagerelative humidity (%) | 75.5 | 77.9 | 80.6 | 81.4 | 84.6 | 86.1 | 86.0 | 82.9 | 79.6 | 77.3 | 76.0 | 76.2 | 80.3 |
| Mean monthlysunshine hours | 191.3 | 145.5 | 124.2 | 106.3 | 81.2 | 61.8 | 74.4 | 101.0 | 109.1 | 129.7 | 148.9 | 164.0 | 1,437.3 |
| Source: NIWA Climate Data (sun 1981–2010)[11][12] | |||||||||||||
Chatham Island hosts the only known breeding population of theendemic and critically endangeredmagenta petrel or tāiko (Pterodroma magentae). The seabird was thought to be extinct until 1978, and had a population of under 200 in 2017.[13]
Chatham Island (or "Isle") is featured in the first and in the final chapter ofCloud Atlas, the 2004 novel byDavid Mitchell. The novel was adaptedfor screen in 2012.[14]
The unofficial flag of the Chatham Islands is visible above the New Zealand flag.
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