Visiting local bars in Saint-Omer-en-Chaussee is more fun when you know what the weather holds. These rainfall averages and temperatures can help you decide the best time for bar-hopping. The hottest months are usually August and July, with an average temperature of 17°C, while the coldest months are January and February, with an average of 5°C. Average annual precipitation for Saint-Omer-en-Chaussee is 749 mm.