If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Sarre: The hottest months are usually July and August, with an average temperature of 15°C, while the coldest months are January and February, with an average of -1°C. The snowiest months in Sarre are November, March, August and April, with each month seeing an average of 26 cm of snowfall.