The blazon of the municipal coat of arms is Azure a Crescent Or in bend issuant behind a Cliff Argent.
Geography
Au has an area,, of. Of this area, 42% is used for agricultural purposes, while 4.2% is forested. Of the rest of the land, 47.8% is settled and the remainder is non-productive. The municipality was part of the Unterrheintal district until the creation of the Rheintal Wahlkreis. It is located in a narrow pass between Heldsberg and the Rhein river. It consists of the village of Au and the hamlets of Haslach, Hard and Monstein as well as a portion of the village of Heerbrugg.
Demographics
Au has a population of. , about 33.3% of the population was made up of foreign nationals. Of the foreign population,, 192 are from Germany, 398 are from Italy, 580 are from ex-Yugoslavia, 334 are from Austria, 121 are from Turkey, and 307 are from another country. Over the last 10 years the population has grown at a rate of 5.7%. Most of the population speaks German, with Italian being second most common and Albanian being third. Of the Swiss national languages, 5,577 speak German, 21 people speak French, 190 people speak Italian, and 7 people speak Romansh. The age distribution,, in Au is; 750 children or 11.7% of the population are between 0 and 9 years old and 792 teenagers or 12.4% are between 10 and 19. Of the adult population, 829 people or 12.9% of the population are between 20 and 29 years old. 1,066 people or 16.6% are between 30 and 39, 928 people or 14.5% are between 40 and 49, and 769 people or 12.0% are between 50 and 59. The senior population distribution is 656 people or 10.2% of the population are between 60 and 69 years old, 398 people or 6.2% are between 70 and 79, there are 193 people or 3.0% who are between 80 and 89, and there are 28 people or 0.4% who are between 90 and 99. there were 879 persons who were living alone in a private dwelling. There were 1,458 persons who were part of a couple without children, and 3,475 who were part of a couple with children. There were 400 people who lived in single parent home, while there are 31 persons who were adult children living with one or both parents, 16 persons who lived in a household made up of relatives, 33 who lived household made up of unrelated persons, and 117 who are either institutionalized or live in another type of collective housing. In the 2007 federal election the most popular party was the SVP which received 39.6% of the vote. The next three most popular parties were the CVP, the FDP and the SP. The entire Swiss population is generally well educated. In Au about 69% of the population have completed either non-mandatory upper secondary education or additional higher education. Out of the total population in Au,, the highest education level completed by 1,459 people was Primary, while 2,500 have completed Secondary, 683 have attended a Tertiary school, and 243 are not in school. The remainder did not answer this question. The historical population is given in the following table:
year
population
1837
917
1850
875
1900
1,314
1910
2,437
1950
2,636
1970
4,944
1990
5,778
Economy
, Au had an unemployment rate of 2.84%. , there were 39 people employed in the primary economic sector and about 15 businesses involved in this sector. 2,228 people are employed in the secondary sector and there are 93 businesses in this sector. 2,013 people are employed in the tertiary sector, with 288 businesses in this sector. the average unemployment rate was 5.6%. There were 424 businesses in the municipality of which 103 were involved in the secondary sector of the economy while 307 were involved in the third. there were 1,254 residents who worked in the municipality, while 2,127 residents worked outside Au and 3,720 people commuted into the municipality for work.
Religion
From the, 3,589 or 56.0% are Roman Catholic, while 1,406 or 21.9% belonged to the Swiss Reformed Church. Of the rest of the population, there is 1 individual who belongs to the Christian Catholic faith, there are 113 individuals who belong to the Orthodox Church, and there are 121 individuals who belong to another Christian church. There is 1 individual who is Jewish, and 529 who are Islamic. There are 38 individuals who belong to another church, 411 belong to no church, are agnostic or atheist, and 200 individuals did not answer the question.
