On 14 November 1990, Alitalia Flight 404 crashed into Stadlerberg Mountain near Weiach while attempting to land at Zurich Airport.

Of the rest of the land, 11.7% is settled (buildings or roads) and the remainder (1.9%) is non-productive (rivers, glaciers or mountains).

At the time, the village comprised 16 households, with 48 inhabitants over the age of 15 liable to pay tax.

Between 1634 and 1760, having been requested to do so by the Zürich authorities, the priests kept detailed records of population size, albeit with sporadic intervals.

Over the centuries, the population size has been closely linked to the profitability of the land, since exports were rare.

The resident population oscillated between 500 and 750 persons, making Weiach the largest parish in Neuamt.

From the end of the 17th Century onwards, many began to look for work outside Weiach, resulting in emigration.

The start of urbanisation can be seen from the explosion in the number of single person households from 1990 (an increase of 132 per cent).

A large-scale construction project was planned at the end of 2007 to build a further 55 apartment blocks in the Bedmen area.