Saint-Julien-sur-Reyssouzè (French pronunciation: [sɛ̃ ʒyljɛ̃ syʁ ʁɛsuz], literally Saint-Julien on Reyssouze) is a commune in the Ain department in eastern France.

The average annual temperature in Saint-Julien-sur-Reyssouze is 11.8 °C (53.2 °F).

The average annual rainfall is 1,014.0 mm (39.92 in) with November as the wettest month.

The temperatures are highest on average in July, at around 21.0 °C (69.8 °F), and lowest in January, at around 3.0 °C (37.4 °F).

This Ain geographical article is a stub.