Wildhaus-Alt St. Johann is a municipality in the Wahlkreis (constituency) of Toggenburg in the canton of St. Gallen in Switzerland. It was formed on 1 January 2010 through the merger of Alt St. Johann and Wildhaus.

Demographics

The former municipalities that would become Wildhaus-Alt St. Johann had a combined population of (as of ).

Historic population

The historical population is given in the following table:

Weather

Wildhaus has an average of 157 days of rain or snow per year and on average receives 1640 mm of precipitation. The wettest month is August during which time Wildhaus receives an average of 202 mm of rain or snow. During this month there is precipitation for an average of 14.7 days. The month with the most days of precipitation is June, with an average of 15.8, but with only 199 mm of rain or snow. The driest month of the year is October with an average of 100 mm of precipitation over 14.7 days.

Heritage sites of national significance

The paleolithic cave, Wildenmannlisloch in Alt St. Johann and the birthplace of the Reformer Huldrych Zwingli at Lisighus 167 in Wildhaus are listed as Swiss heritage sites of national significance.