When you're travelling with pets, keeping tabs on the weather can help you make the trip more safe and fun for everyone. The hottest months are usually July and August, with an average temperature of 16°C, while the coldest months are January and February, with an average of 1°C. The rainiest months in Grand'Combe-Chateleu are June, May, July and December, with each month seeing an average of 186 mm of rainfall.