Saint-Hilaire-sur-Helpe has an oceanic climate (Köppen climate classificationCfb). The average annual temperature in Saint-Hilaire-sur-Helpe is 10.5 °C (50.9 °F). The average annual rainfall is 802.4 mm (31.59 in) with August as the wettest month. The temperatures are highest on average in July, at around 18.5 °C (65.3 °F), and lowest in January, at around 3.1 °C (37.6 °F). The highest temperature ever recorded in Saint-Hilaire-sur-Helpe was 39.0 °C (102.2 °F) on 25 July 2019; the coldest temperature ever recorded was −18.5 °C (−1.3 °F) on 7 January 2009.
Climate data for Saint-Hilaire-sur-Helpe (1991−2020 normals, extremes 2004−present)