The GR20 refuges are staffed from mid-May to early October: from 16 May to 4 October in 2026. The 2027 dates have not yet been announced.
Late May – mid-June: snow
In spring, snowfields linger above 2,000 m. At the end of April 2026, there was still snow around Lac de la Muvrella (stage 3), on the Pointe des Éboulis (stage 4), at the Bocca alle Porte (stage 7) and at the Bocca Muratellu (stage 9). The FFRandonnée was then recommending crampons, hiking boots and a lightweight ice axe. Check with the Park before setting off early in the season.
Mid-June – August: heat, storms and wildfires
- Heat on the low-lying stages (Calenzana, Conca): set off at dawn.
- Storms are frequent in the afternoon: the 2015 accident in the Cirque de la Solitude happened after a violent storm. Stay off the ridges when a weather warning is in force.
- Water: streams dry up, and the Prati – Usciolu stage is short of water in July and August.
- Wildfire risk: mountain areas may be closed at any time, as happened in July 2026.
September: the best compromise
Milder temperatures, fewer storms and superb light. Along with early June, it is also the busiest period on the booking platform: book as soon as bookings open.
Keeping an eye on the weather
Check the Météo-France mountain forecast for Corsica every evening, and ask the wardens for advice. In strong winds or stormy weather, take the valley route rather than the ridge variant on stage 8.
Other guides
- How to book GR20 refuges in 2027: a step-by-step guide
- Cirque de la Solitude on the GR20: what to know in 2027
- GR20 budget: how much does the trek across Corsica cost?
- GR20 transport: getting to Calenzana and leaving Conca
- GR20 camping and bivouac rules: what you need to know
- GR20 safety and water: rescue, phone signal, water points
- GR20 packing list: the complete gear checklist
- GR20 North or GR20 South: which half should you choose?
- How to train for the GR20: fitness level and training plan