In Réunion, overseas departments of France located in the Indian Ocean south of the Equator, the climate is tropical, with a hot and humid season from December to March, and a cool season from June to September, ie the austral winter.
There are, however, significant differences between the zones. The south-east trade winds blow all year round, but especially in the cool season. The interior of the island is mountainous, so the winds bring rainfall on the eastern slopes throughout the year, while the western slopes are rainy only in the hot and humid season, while in the rest of the year they receive a few rains, and are even a bit warmer. So the island is basically divided into two, and the northwest coast, where we find also the most beautiful beaches, is almost dry.
In the capital St. Denis, located on the north coast, from June to September, daytime temperatures drop to around 25/26 °C (77/79 °F), and night-time temperatures to around 18/19 °C (64/66 °F), but sometimes they can drop to 13/14 °C (55/57 °F). On the contrary, during the warmer period, from January to March, the temperature hovers around 30 °C (86 °F) during the day, and around 23/24 °C (73/75 °F) at night.
Here are the average temperatures.
Average temperatures - Saint-Denis

Saint-Denis	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Saint-Denis	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	24	24	23	22	21	19	18	18	19	20	21	22
Max (°C)	30	30	30	29	28	26	25	25	26	27	28	29
Min (°F)	75	75	73	72	70	66	64	64	66	68	70	72
Max (°F)	86	86	86	84	82	79	77	77	79	81	82	84

The rains in Réunion occur in the form of brief but intense showers, called avalasses. In the interior, the elevations enhance the formation of thunderclouds in the slopes exposed to the wind, while partially sheltering the leeward side, so that in inland areas the rainfall can even reach 6 metres (235 inches) per year, in addition, the eastern coast, where rainfall exceeds 3,000 millimeters (120 inches) per year, is much more rainy than the western one, from Le Port to Saint-Pierre, where it drops below 1,000 mm (40 in).
In Saint-Denis, on the north coast, the situation is intermediate, and 1,600 mm (65 in) of rain per year fall. The rains are most abundant from January to March, when generally more than 200 mm (8 in) per month fall along the coast, and even 1,000 mm (40 in) per month on inland slopes. Usually the rainiest month is February. However, some showers may occur even in the driest months.
Here is the average precipitation in St. Denis.
Average precipitation - Saint-Denis

Saint-Denis	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Saint-Denis	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	280	350	235	155	95	75	60	60	50	45	70	190	1660
Prec.(in)	11	13.8	9.3	6.1	3.7	3	2.4	2.4	2	1.8	2.8	7.5	65.4
Days	13	14	13	11	10	7	9	10	8	7	6	11	119

In the interior of the island there is a town, Cilaos, at 1,200 metres (3,900 feet) above sea level, inside the caldera of the volcano Piton des Neiges, where from 15 to 16 March 1952, even 1,870 mm (73.5 in) of rain fell, beating the world record of the highest 24-hour rainfall. However, in Cilaos 1,800 mm (70 in) of rain per year fall, with a maximum of 600 mm (23.5 in) in February, and less than 100 mm (4 in) per month from May to November.
Here are the average temperatures.
Average temperatures - Cilaos

Cilaos	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cilaos	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	15	16	15	13	11	8	7	7	8	10	11	13
Max (°C)	25	25	24	24	22	20	19	19	20	22	23	24
Min (°F)	59	61	59	55	52	46	45	45	46	50	52	55
Max (°F)	77	77	75	75	72	68	66	66	68	72	73	75

The volcano Piton des Neiges is 3,069 metres (11,841 feet) high, but despite its name ("snowy peak"), even on the summit it almost never snows.
In the south-east of the island there is another volcano, Piton de la Fournaise, very active, 2,632 metres (8,635 feet) high.
Here are the average temperatures of Bellecombe Pass, located at 2,300 meters (7,500 feet), on the edge of the caldera of Piton de la Fournaise. As you can see, the temperatures are mild in summer, while in winter they are cold.
Average temperatures - Bellecombe

Bellecombe	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Bellecombe	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	10	10	10	8	7	4	3	3	4	6	7	8
Max (°C)	18	18	18	17	15	13	12	13	14	16	18	18
Min (°F)	50	50	50	46	45	39	37	37	39	43	45	46
Max (°F)	64	64	64	63	59	55	54	55	57	61	64	64

Here, precipitation amounts to even 5,200 mm (205 in) per year, of which more than 500 mm (20 in) per month from January to April, but heavy downpours are also possible in July and August (and a bit less from September to November).
For the great amount of rain falling in the interior, there are forests, as well as numerous streams (some of which are used for rafting), which give rise to waterfalls. The interior with its spectacular landscape is protected in a National Park since 2007, while in 2010 the island earned a place in the UNESCO World Heritage Site list.



The amount of sunshine at Réunion is never excellent, nor poor along the coasts, because some cloudiness can form throughout the year, but as we said the rains do not last long, while on the slopes of the volcanoes, the sky is often cloudy.
Sunshine - Saint-Denis

Saint-Denis	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Saint-Denis	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	7	7	7	7	7	7	7	7	7	6	7	7

The island of Réunion is located in the path of tropical cyclones, whose season runs from November 1 to May 15, although they are most common from late December to mid-April.



The temperature of the sea is high enough for swimming all year round, however, it decreases to 23/24 °C (73/75 °F) between July and October.
Sea temperature - Saint-Pierre

Saint-Pierre	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Saint-Pierre	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	27	28	27	27	26	25	24	23	23	24	25	27
Sea (°F)	81	82	81	81	79	77	75	73	73	75	77	81

There are surfing spots, or diving can be done in the coral reef, even though there is the danger represented by currents and sharks.


The best time to visit Réunion is the austral winter, ie from mid-May to October, because it's the coolest and driest, and out of the period of hurricanes. However, for beach life, during this period the weather can be a bit cool, also because of the trade winds, which blow especially along the eastern and southern coasts. You can then take advantage of the mild temperatures to explore the interior of the island (but remember that in winter in the high mountains it is cold).
Or you can choose the second half of May and the month of October, which are slightly warmer, and in any case choose the north-west coast, which is more sheltered from the wind.
The orchids bloom especially at the end of winter, therefore between the end of September and October.

If you want to go in January and February, a period which in any case is not recommended because of the risk of cyclones, you can choose the west coast, from Le Port to Saint-Pierre, which is less rainy even during this period.


In winter (May to October): on the coast, light clothes, a sweatshirt or sweater, a light jacket, a scarf for the breeze; in Cilaos, spring/autumn clothes, raincoat; to climb mountains, hiking boots, fleece, jacket, raincoat.
In summer (December to arch): along the coast, tropics-friendly, loose fitting clothing, light shirts and pants of natural fibres (cotton, linen), light sweatshirt for the evening, light raincoat or umbrella; in Cilaos, light clothes, sweatshirt or sweater, light jacket, raincoat.