You may know that the best time to do the Gr20 is between June and September, but that doesn’t give you a 100% guarantee of good weather. Surveying this high mountain route, which crosses Corsica over more than 180 km, is in itself a real challenge. The length, the ruggedness of the trail and some of the dangerous sections can make this a testing trek. In this article, we’ll go into a little more detail about the weather conditions around the GR20 and what the route looks like at different times of year.
Fire risks on the GR20
From mid-June to mid-September, certain Corsican massifs can be dangerous, depending on the weather conditions for certain stages of the GR20. The slightest spark can cause a fire! We invite you to follow this fire risk map, updated every day in the summer at 6 p.m. for the next day: http://emz.pont-entreprises.org/maps/2A/
Extremely changeable weather on the GR20
As the GR20 is a high mountain trail, the weather can change very quickly from “very fine” to “very nasty”. From north to south, there can be a great diversity of landscapes and climates: Mediterranean climate but also a real high mountain climate like in the Alps.
The climate at lower altitudes is relatively dry, particularly in summer. At higher altitudes and on the peaks, it is damp and cold. And there can be rain and even a risk of thunderstorms, not to mention the sometimes violent winds and fog. At night on the GR20, it can be very cold even in summer. So make sure you bring warm clothing. Caution is advised, and you should check the Corsican weather forecast before setting off.
Of course, you’ll need to bring the necessary equipment to hike in the rain and stay waterproof, but above all you’ll need to be wise in the face of the mountains. You’ll soon find yourself wearing a “bare-arm T-shirt” instead of “k-way waterproof trousers”.
Don’t put yourself in any danger: in summer it can get very cold if the weather turns nasty (strong winds, cold rain, storms, etc.). If you’re planning to do the GR20 in 16 days, you won’t know before you set off whether you’ll have 15 days of good weather, so you’ll have to adapt to the weather along the way.
Here’s some information to help you find out the weather on the GR20 as you go along. Cross-check the information to have a better chance of obtaining a realistic forecast. And don’t hesitate to consult the weather reports posted by the wardens in the refuges.
GR20 North weather
- Weather at Calenzana: click here / See on Météo Ciel
- Weather at Asco (ski resort, end of stage 3): click here / See on Météo Ciel
- Weather at Vergio: click here to see the weather at the Col de Vergio
- Weather at Vizzavone (halfway point): click here
- Facebook page: https: //www.facebook.com/CorseEvenementsMeteo
GR20 South weather forecast
- Weather on Vizzavone (half way): click here
- Weather at Bavella: click here
- Weather in the Incudine massif: click here
- Weather in Conca: click here / See on Météo Ciel
- Facebook page: https: //www.facebook.com/CorseEvenementsMeteo
The GR20 in June
Late spring is the ideal time to do the GR20. Between June and July, the scenery is sublime, even though it can be cool, particularly when crossing the crests. In the Tavignano massif, you can admire Lake Nino with its magnificent pozzines (large plains of bright green grass), come across wild hair and a few foxes if you’re lucky. At this time of year, streams are abundant, while snowfalls persist at certain points along the route. Discover all the temperatures and weather conditions on the GR20 in June
Températures calculées à partir des données météos relevées à Corte. Estimation de baisse des températures ressenties de 0.6° tous les 100m d'altitudeAltitude (en mètres) | + haut de (en m) | JUIN 2014 | JUIN 2015 | JUIN 2016 | JUIN 2017 | JUIN 2018 | Moyenne | |
---|---|---|---|---|---|---|---|---|
Calvi | 60 | Référence | 16° | 17° | 17° | 19° | 17° | 17° |
Corte | 460 | Référence | 13° | 13° | 13° | 14° | 13° | 13° |
Calenzana | 280 | 220 | 15° | 15° | 15° | 17° | 16° | 16° |
Ortu di u Piobbu | 1520 | 1060 | 6° | 6° | 6° | 8° | 6° | 6° |
Carrozzu | 1270 | 810 | 7° | 8° | 8° | 9° | 8° | 8° |
Station d’Asco Stagnu | 1422 | 962 | 6° | 7° | 7° | 8° | 7° | 7° |
Tighjettu | 1683 | 1223 | 5° | 5° | 5° | 6° | 5° | 5° |
Ciottulu di i Mori | 1997 | 1537 | 3° | 3° | 3° | 4° | 3° | 3° |
Manganu | 1600 | 1140 | 5° | 6° | 6° | 7° | 5° | 6° |
Petra piana | 1842 | 1382 | 4° | 4° | 4° | 5° | 4° | 4° |
l’Onda | 1431 | 971 | 6° | 7° | 7° | 8° | 6° | 7° |
Vizzavona | 954 | 494 | 9° | 10° | 10° | 11° | 10° | 10° |
E Capannelle | 1586 | 1126 | 5° | 6° | 6° | 7° | 5° | 6° |
Prati | 1820 | 1360 | 4° | 4° | 4° | 6° | 4° | 4° |
Usciolu | 1750 | 1290 | 4° | 5° | 5° | 6° | 4° | 5° |
Matalza | 1410 | 950 | 6° | 7° | 7° | 8° | 7° | 7° |
Asinau | 1536 | 1076 | 6° | 6° | 6° | 7° | 6° | 6° |
I Paliri | 1055 | 595 | 9° | 9° | 9° | 11° | 9° | 9° |
Conca | 250 | 230 | 13° | 13° | 13° | 14° | 13° | 13° |
Figari | 20 | Référence | 15° | 15° | 14° | 15° | 15° | 15° |
The GR20 in summer
In summer, during the months of July and August, apart from the crowds of Julyers and Augusters who can be a nuisance to some, the heat can be really oppressive at times. The weather is dry and the sun beats down hard. So remember to protect your eyes and head, and above all to keep regularly hydrated. In terms of weather, temperature and crowds, July and August are similar.
The weather on the GR20 in September
From September onwards, the number of visitors drops and the GR20 trail regains its tranquillity. The weather is still fine at this time of year, and even if the water sources are rarer, the views of the sea and the mountains of Corsica are simply breathtaking. Planning to do the GR20 in September 2024? Here’s more information
What does the GR20 look like in winter?
From October until May, the GR20 presents a radically different face. At the height of winter, the path is completely covered in snow. It then becomes a ski touring route now known as the Alta Strada! You’ll glide over a blanket of snow across the ridges and admire the colours and atmosphere that are so unique to Corsican winters. Although quite feasible, crossing the GR20 in winter is for experienced hikers or winter mountaineering specialists.
The ski resort of Asco
In 1964, at the instigation of the mayor of the time, the small ruined sheepfold on the heights of the village of Asco was gradually transformed into a ski resort. With its chalets, ski lifts and ski runs, the Haut Asco winter resort was the pride of Corsica. The resort’s destiny suddenly changed when an avalanche killed a group of schoolchildren in 1969, followed by major flooding in autumn 1992. Fortunately, the resort reopened in 2015, offering its new customers a modern structure and state-of-the-art facilities.
Temperature at night on the GR20?
Corté is situated at an altitude of 400 metres. We have used the data provided by infoclimat to calculate the average temperatures on the GR20 at each bivouac. To estimate the temperatures at night on the GR20, we then applied the rule of -0.65° for every 100 metres of difference in altitude.
From here, you can consult :
- average minimum temperatures on the GR20 in April
- average minimum temperatures on the GR20 in May
- average minimum temperatures on the GR20 in June
- average minimum temperatures on the GR20 in July
- average minimum temperatures on the GR20 in August
- average minimum temperatures on the GR20 in September