Semaphore, SA
By Lauren McCaleb · Reviewed by Dylan Duncan ·
Semaphore is a historic seaside suburb on the Lefevre Peninsula, about 14 km north-west of central Adelaide on the Gulf St Vincent coast. Its unusual name dates to 1851, when a publican erected a tall signal mast — a semaphore — to flag the arrival of ships to Port Adelaide. Surveyed in 1849, it grew through the late nineteenth century into a popular seaside resort as a bridge, railway and tram connected it to the city. Today it is a relaxed beach suburb known for its wide sandy beach, a long jetty dating from 1860, the restored Odeon Star cinema and a broad esplanade that hosts events such as the annual Kite Festival.
More advantaged than the national average
Semaphore is more socio-economically advantaged than about 69% of the 14,462 Australian suburbs we score, based on the ABS SEIFA index (raw score 1021, where about 1000 is the national average).
A socio-economic measure from ABS Census data — not a measure of how good a suburb is to live in or visit. How we calculate this.
Semaphore at a glance
- Population (2021)
- 2,749
- Median age
- 50
- Median weekly household income
- $1,718
- SEIFA score
- 1021
- Coordinates
- -34.8385, 138.4831
Semaphore demographics (2021 Census)
The figures below profile Semaphore using the Australian Bureau of Statistics 2021 Census; every percentage is a share of a clearly stated Census count, so each one traces back to the source. At a glance, the largest age group is mid-life (45–64) at 39%, 30% of homes are rented, and 23% of residents were born overseas.
Age profile
| Age group | People | Share |
|---|---|---|
| Children (0–14) | 312 | 11% |
| Youth (15–24) | 253 | 9% |
| Young adults (25–44) | 565 | 21% |
| Mid-life (45–64) | 1,060 | 39% |
| Seniors (65+) | 555 | 20% |
Share of the 2,745 people counted by age.
Housing and households
| Tenure | Dwellings | Share |
|---|---|---|
| Owned outright | 400 | 35% |
| Owned with a mortgage | 378 | 33% |
| Rented | 345 | 30% |
| Dwelling type | Dwellings | Share |
|---|---|---|
| Houses | 744 | 65% |
| Townhouses & semis | 261 | 23% |
| Flats & apartments | 128 | 11% |
Tenure and dwelling shares are of the roughly 1,142 occupied private dwellings in Semaphore.
- Median weekly rent
- $320
- Median monthly mortgage
- $1,733
- Average household size
- 2.2 people
- Median weekly family income
- $2,362
- Median weekly personal income
- $857
Community and culture
- Born overseas
- 598 (23%)
- Speaks a language other than English at home
- 220 (8%)
- Aboriginal and/or Torres Strait Islander
- 51 (2%)
Work and education
- Completed Year 12
- 1,395 (59%)
- Labour-force participation
- 62.2%
- Unemployment rate
- 4.2%
- Employed full-time
- 867
- Employed part-time
- 514
Source: ABS Census of Population and Housing, 2021 (General Community Profile, by Suburb and Locality). © Australian Bureau of Statistics, released under CC BY 4.0. How we group bands and derive each share is set out on our methodology page.
Weather and climate in Semaphore
Based on 2014–2023 records, the warmest month in Semaphore is January (average daytime high around 28.7°C) and the coolest is July (around 14.6°C). The area receives roughly 542 mm of rain across the year.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 28.7°C | 17.4°C | 32 mm |
| Feb | 27.6°C | 17°C | 23 mm |
| Mar | 25.6°C | 15.8°C | 18 mm |
| Apr | 22.4°C | 13.5°C | 48 mm |
| May | 18.1°C | 11°C | 63 mm |
| Jun | 15.4°C | 8.8°C | 67 mm |
| Jul | 14.6°C | 8°C | 64 mm |
| Aug | 15.3°C | 8.1°C | 69 mm |
| Sep | 17.9°C | 9.6°C | 49 mm |
| Oct | 21.6°C | 11.7°C | 42 mm |
| Nov | 23.9°C | 13.4°C | 41 mm |
| Dec | 26.7°C | 15.4°C | 26 mm |
Climate normals, 2014–2023 (Open-Meteo, ERA5 reanalysis).
Common questions about Semaphore
Where is Semaphore?
Semaphore is a suburb of South Australia, Australia.
What is the population of Semaphore?
At the 2021 Census, Semaphore had a population of about 2,749.
Is Semaphore an advantaged area?
Semaphore has an ABS SEIFA score of 1021, where about 1000 is the national average — higher scores indicate greater relative socio-economic advantage. That gives it a Suburb Score of 69 out of 100 — more socio-economically advantaged than about 69% of Australian suburbs.
What is the weather like in Semaphore?
Semaphore has average daytime highs of about 21.5°C and overnight lows of about 12.5°C, with roughly 542 mm of rain across the year (based on 2014–2023 climate normals).
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