Weather is probably a major factor when you plan your trip to Le Grand-Bornand, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually July and August, with an average temperature of 14°C, while the coldest months are January and February, with an average of -2°C. The snowiest months in Le Grand-Bornand are October, September, May and December, with each month seeing an average of 14 cm of snowfall.