Within his responsibilities were spatial planning, housing, traffic and transport, and economic affairs.

Wienen was also member of the executive committee of the region Holland Rijnland, of which Katwijk is a part.

On 21 September 2016, Wienen exchanged Katwijk for the city Haarlem where he succeeded Bernt Schneiders as mayor.

[2] Presumably as a result of his strict stance towards motor cycling gangs Jos Wienen was threatened from October 2018 onwards.

Some citizens from Haarlem even organised a gathering on the Grote Markt to support the mayor and pray for the threats to cease.