Silhac is a commune in the Ardèche department in the Auvergne-Rhône-Alpes region of southern France.

In 2010, the climate of the commune was a altered Mediterranean climate type, according to a French National Centre for Scientific Research study based on a series of data covering the period 1971-2000.

The average annual cumulative precipitation is 1,048 mm , with 7.7 days of precipitation in January and 5.4 days in July.

The region is characterized by good sunshine in the summer (fraction of insolation > 60%), a high annual temperature amplitude (4 to 20  °C), dry air in all seasons, stormy in summer, strong winds (mistral), and high rainfall in autumn (250 to 300 mm).

[4] The Dunière, a 24 km[5] watercourse which runs alongside the municipal territory, is a tributary of the Eyrieux, a river which borders the southern part of its territory.