Herisau () is a municipality and the capital of the canton of Appenzell Ausserrhoden in Switzerland. It is the seat of the canton's government and parliament; the judicial authorities are situated in Trogen.
The central hamlet and the houses around the central square, the Protestant church of 1580, the houses Wetter and zur Rose (both 1737), the hamlet Schwänberg and the government building with the state archive are listed as heritage sites of national significance.
Together with other Alpine towns Herisau engages in the Alpine Town of the Year Association for the implementation of the Alpine Convention to achieve sustainable development in the Alpine Arc.
Herisau was awarded Alpine Town of the Year 2003.
History
thumb|Aerial view from 300 m by [[Walter Mittelholzer (1920)]]
Herisau was first mentioned in 837 as Herinisauva, Over the last 10 years the population has decreased at a rate of -5.2%. Most of the population () speaks German (87.0%), with Serbo-Croatian being second most common (3.8%) and Italian being third (3.4%).
, the gender distribution of the population was 49.6% male and 50.4% female.
In the 2007 federal election the FDP received 76.7% of the vote.
{| class="wikitable"
|-
! year
! population
! Swiss Citizens
! % German Speaking
! % Protestant
! % Roman Catholic
|-
| 1667 || align="center" | 3,021 || || || ||
|-
| 1734 || align="center" | 4,816 || || || ||
|-
| 1780 || align="center" | 5,933 || || || ||
|-
| 1813 || align="center" | 6,863 || || || ||
|-
| 1830 || align="center" | 7,014 || || || ||
|-
| 1850 || align="center" | 8,387 || align="center" | 8,189|| || align="center" | 97.1% || align="center" | 2.9%
|-
| 1870 || align="center" | 9,705 || align="center" | 9,481|| || align="center" | 92.9% || align="center" | 6.2%
|-
| 1888 || align="center" | 12,937 || align="center" | 12,082|| align="center" | 98.9% || align="center" | 87.7% || align="center" | 12.0%
|-
| 1900 || align="center" | 13,497 || align="center" | 12,426|| align="center" | 98.1% || align="center" | 84.9% || align="center" | 14.7%
|-
| 1910 || align="center" | 15,336 || align="center" | 13,550|| align="center" | 95.0% || align="center" | 81.4% || align="center" | 18.0%
|-
| 1930 || align="center" | 13,599 || align="center" | 12,784|| align="center" | 98.4% || align="center" | 82.8% || align="center" | 16.6%
|-
| 1950 || align="center" | 13,407 || align="center" | 12,819|| align="center" | 97.6% || align="center" | 80.6% || align="center" | 18.6%
|-
| 1970 || align="center" | 14,597 || align="center" | 12,128|| align="center" | 86.0% || align="center" | 66.3% || align="center" | 31.3%
|-
| 1990 || align="center" | 15,624 || align="center" | 12,731|| align="center" | 84.6% || align="center" | 55.3% || align="center" | 34.1%
|-
| 2000 || align="center" | 15,882 || align="center" | 12,535|| align="center" | 87.0% || align="center" | 48.3% || align="center" | 32.1%
|-
|}
Weather
Herisau has an average of 154 days of rain per year and on average receives of precipitation. The wettest month is July during which time Herisau receives an average of of precipitation. During this month there is precipitation for an average of 13.9 days. The month with the most days of precipitation is May, with an average of 15.3, but with only of precipitation. The driest month of the year is February with an average of of precipitation over 13.9 days.
Economy
Herisau is located in the centre of eastern Switzerland. As early as 1537 it established itself as an important centre of trade and commerce.
Herisau has an unemployment rate of 2.01%. , there were 340 people employed in the primary economic sector and about 115 businesses involved in this sector. 2,959 people are employed in the secondary sector and there are 189 businesses in this sector. 4,505 people are employed in the tertiary sector, with 651 businesses in this sector.