Giron is a commune in the Ain department in eastern France. Giron has an oceanic climate. The average annual temperature in Giron is 8.4 °C. …Giron is a commune in the Ain department in eastern France. Giron has an oceanic climate. The average annual temperature in Giron is 8.4 °C. The average annual rainfall is 1,672.4 mm with December as the wettest month. The temperatures are highest on average in July, at around 17.1 °C, and lowest in January, at around 0.3 °C. The highest temperature ever recorded in Giron was 36.5 °C on 13 August 2003; the coldest temperature ever recorded was −23.0 °C on 12 January 1987.