Geography
[edit]
Geologically, Bruny Island actually consists of two land masses—North Bruny and South Bruny—that are joined by a long, narrow, sandy isthmus, often referred to as "The Neck". The island has a total length of approximately 50 kilometres (30 miles). The holiday village of Dennes Point is located in North Bruny, while South Bruny is the site of the towns of Alonnah, Adventure Bay, and Lunawanna.
Aerial perspective of the isthmus of Bruny Island, looking north
Outside its settlements, the island is covered with grazing fields and large tracts of dry eucalyptus forest. Inland forests have been logged, but other large sections—mostly along the southeastern coast—are preserved as the South Bruny National Park. While the seaward side of the island features two long beaches—Adventure Bay and Cloudy Bay—it is for the most part extremely rugged, with cliffs of dolerite over 200 metres (660 ft) AHD in altitude. Bruny's channel side is more sheltered and a favourite fishing and recreational boating area for local and interstate visitors. Adventure Bay is located on the eastern side of the isthmus, while Isthmus Bay is located on the western side.
Access to the island is by vehicular ferry, funded by the State Government. Since 1954, four vessels have operated the Bruny Island Ferry service between the island and Kettering on the mainland. The service currently uses the vessel, Mirambeena, which is plied by a Voith-Schneider propulsion system rather than a conventional propeller. There is a public airfield, Bruny Island Airport located on North Bruny, just north of The Neck, however the small runway is mostly suited to small aircraft, and there are no scheduled flights.
The d'Entrecastaux Channel region, sheltered by Bruny Island, is increasingly subject to foreshore erosion. Some areas have begun sandbagging to reduce the effects.
Climate[edit]
Bruny Island has a cool oceanic climate (Köppen: Cfb) with short, cool summers and chilly, wet winters with snowfalls. The island is near-constantly buffeted by cold fronts off the Roaring Forties, even through the height of summer. The island is very windy with a mean 3 pm wind speed of 27.8 km/h (17.3 mph); cloud cover is likewise great, with 242 cloudy days and 19.2 clear days annually. Rain falls on an average of 200 days a year.
An extreme event on 15 November 2021 saw a fall of snow to beach level on the island, though historical temperature data indicate this may have also happened prior to that event − and perhaps even in the early summer.
Climate data for Cape Bruny Lighthouse (1991–2020, extremes 1923–2026); 43.49° S, 147.15° E
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Record high °C (°F)
39.3(102.7)
39.0(102.2)
39.7(103.5)
28.7(83.7)
24.5(76.1)
20.0(68.0)
19.1(66.4)
22.4(72.3)
26.5(79.7)
31.4(88.5)
35.0(95.0)
39.2(102.6)
39.7(103.5)
Mean daily maximum °C (°F)
19.1(66.4)
19.1(66.4)
18.0(64.4)
16.0(60.8)
14.1(57.4)
12.2(54.0)
11.8(53.2)
12.4(54.3)
13.7(56.7)
14.9(58.8)
16.2(61.2)
17.7(63.9)
15.4(59.8)
Mean daily minimum °C (°F)
12.3(54.1)
12.4(54.3)
11.6(52.9)
10.0(50.0)
8.7(47.7)
7.1(44.8)
6.6(43.9)
6.5(43.7)
7.4(45.3)
8.3(46.9)
9.7(49.5)
10.7(51.3)
9.3(48.7)
Record low °C (°F)
1.7(35.1)
2.8(37.0)
1.7(35.1)
0.3(32.5)
0.0(32.0)
−1.4(29.5)
−1.7(28.9)
−2.2(28.0)
−2.0(28.4)
−1.7(28.9)
0.6(33.1)
0.6(33.1)
−2.2(28.0)
Average precipitation mm (inches)
57.1(2.25)
57.3(2.26)
64.8(2.55)
68.7(2.70)
76.5(3.01)
81.7(3.22)
90.1(3.55)
108.2(4.26)
81.6(3.21)
76.2(3.00)
67.8(2.67)
65.9(2.59)
895.9(35.27)
Average precipitation days (≥ 0.2 mm)
13.2
12.7
15.2
15.6
17.4
17.5
19.2
20.5
18.3
18.7
16.2
15.6
200.1
Average afternoon relative humidity (%)
70
70
70
72
73
76
75
71
69
70
71
71
71
Average dew point °C (°F)
11.0(51.8)
11.3(52.3)
10.4(50.7)
8.9(48.0)
7.8(46.0)
6.7(44.1)
6.2(43.2)
5.6(42.1)
6.1(43.0)
7.4(45.3)
8.7(47.7)
9.8(49.6)
8.3(47.0)
Source 1: Cape Bruny Lighthouse (means 1991–2020, extremes 1923–2021)
Source 2: Cape Bruny (extremes 1997–2026)