December to February: Winter is peak ski season in the French Alps, which means booking your vacation early to secure the best accommodation; ski enthusiasts should keep in mind the February school ski break. Expect plenty of snow, with temperatures ranging from 14°F to 41°F.
March to May: Typically, the spring climate in the northern Alps is wetter, the southern Alps drier and warmer, with spring arriving sooner in the south. March and April are still good times for skiing at higher altitudes, while the best time to hike is May. Temperatures range from 23°F to 50°F, with increasing hours of sunshine.
June to August: Summer transforms the French Alps into one big outdoor playground for hiking, mountain biking, and climbing, among other pursuits. Temperatures range from 59°F to 77°F, with 10-12 hours of sunshine daily. Be aware, however, of sudden storms in the mountains.
September to November: Autumn offers much cooler weather, with temperatures ranging from 41°F to 59°F, although September is by far the best time of year to walk in the Alps. Rainfall is moderate, averaging 1.6-2.8 inches per month, and you can expect 7-9 hours of sunshine.