Climate Réunion
With its seaside protected by the lagoon, its primary jungles, its savannah slopes and its 3,070 m high peak, the island's multiple reliefs give rise to more than two hundred microclimates. Mountain climate towards Dimitile, hot and dry tropical climate towards Saint-Gilles, hot and humid tropical climate towards Saint-André, temperate and cool in the cirques. It is therefore almost impossible to rely solely on the weather forecast, which only gives the broad outlines. However, it is a good advice if you are planning a long hike and as far as heavy rain and possible cyclone and thunderstorm warnings are concerned, for the rest, the best thing to do is to get out as soon as the weather is nice because the weather can change quickly. The advantage being that if it rains where you are, it is often enough to drive a few kilometres to find the good weather again.
The windward coast and the leeward coast
Like most islands in the southern hemisphere, Reunion Island presents a very marked opposition between its green and rainy east coast and its arid and dry west coast. This is known as the "windward coast" to the east, swept along by the trade winds from the east and south-east, which bring their share of rain, creating a green and exuberant landscape little affected by the changing seasons. Conversely, the west coast, known as the "leeward coast", receives very little rain, except in its heights, and presents savannah landscapes adorned in yellow and red colours reminiscent of the overwhelming heat of the midday sun in summer. Two coasts, two worlds, which has allowed tourism to diversify: in the West, seaside resorts attract travellers seeking rest and relaxation with their feet in the water, while the East, much wilder, is more oriented towards river leisure activities - canyoning, fishing, swimming, hiking, climbing waterfalls - and the discovery of abundant vegetation.
The freshness of the heights
While the weather is always good in the Lowlands, rarely less than 25°C during the day all year round, whether in the East or West, it can quickly become cool or even cold in the Highlands, with temperatures dropping by roughly 8 °C every 1 000 m. Don't forget that it can snow or frost at the volcano, the Piton des Neiges or the Col des Bœufs in winter. While this may frighten the tourist in search of sunshine, many locals have moved from the Bas, which has fans and air conditioners all year round, to the mid-slopes where the houses all have their chimneys and where it's a real treat to fall asleep under a thick duvet. As early asXIXe siècle, the bourgeois had their second home at altitude (the famous "change of air") to escape the suffocating promiscuity of the Bas. So remember to always have a sweater and adequate clothing if you go to the mountains. Please note that in the rainy season, the Hauts tend to get covered with clouds and fog very early in the day (around 10am), blocking the view until late afternoon. To enjoy the wonderful views, it is best to start your hike at sunrise and then take advantage of the beach at the end of the day to take a warm nap on the sand.
Rainy season and dry season
Reunion Island does not have the four metropolitan seasons, but rather two long distinct seasons: the dry season from April to November and the rainy season from December to March. Each one has its advantages: the dry season offers overall a beautiful sunshine all day long. The air temperature then hovers around 27 °C on the coast, good weather reigns, and the climate is ideal, pleasant, ventilated by the light breeze of the trade winds. However, the evenings are cool, especially in the high mountains, where gloves and scarves will not be too much in the evenings and mornings. From July to September, it is also the whale season, an unforgettable spectacle. However, the sea is more agitated, the southern swell creating big waves that are beautiful to watch but dissuasive for swimming and the water temperature drops to 20-25 °C. The dry season trips will therefore be more oriented towards cultural activities, hiking and boat trips rather than idleness on the beach.
In the wet season, from December to March, the temperature rises to 30 °C with peaks of 35-40 °C in some areas such as the Port and Saint-Paul. The sea then climbs to 27-28°C and one could easily spend the day basking in the water. While these heats can be heavy, don't forget that the southern summer is still the best time to boycott the cold winter in the metropolis! The months of November and December are also the months when many colourful trees bloom, such as the flamboyant red-coated tree and the purple-flowered jacaranda, and when "tropical" fruits arrive on the markets: passion fruit, mangoes and, above all, lychees! These little joys are in themselves a reason to travel. On the other hand, as its name suggests, the wet season is also characterized by more frequent rainfall and very changeable weather, which sometimes compromises hiking and mountain outings. It is also the cyclone season.
Random cyclones
While tourists fear the arrival of cyclones because of plane cancellations and the heavy rains they bring, locals tend to look forward to their arrival to "refresh the vegetation". And for good reason, here we are used to the phenomenon, Reunion Island being on the "classic" trajectory of Indian Ocean cyclones. More or less violent, the numerous storms and lows which harass the heavy, damp, humidity-saturated austral summer are considered to be cyclones as soon as the strength of their winds exceeds 117 km/h. One speaks about " intense tropical cyclone " from 166 km/h and about " very intense tropical cyclone " beyond 213 km/h. So many lightning gusts which, being able to blow at more than 300 km/h, are invariably accompanied by torrential rains: it can fall up to 2 200 mm of water in 24h. The barometer falls, the swell breaks out, everyone locks themselves in their homes after having taken, at the first alert, the storm supermarkets by storm to stock up on provisions. If, thanks to the quality of weather forecasts and current infrastructures, "gales" now cause very few victims, they often cause considerable material and natural damage: power cuts, flooding, road damage, destruction of buildings, bridges and forests... So, will it pass or not? Météo France is closely monitoring and triggers alerts according to the evolution of the disturbance. Some cyclones have circled the island for more than a week before dissipating or moving away. After the cyclone, there are still many dangers: roads cut off, gullies overflowing, furious swell, etc. The unexpected is also part of the trip, but everything is well orchestrated, just stay vigilant and inform yourself.
