The climate of the Comoros, archipelago in the Indian Ocean south of the Equator, is tropical, with a hot and rainy season from December to April, in which the north-west monsoon prevails, and a relatively cool and dry season from May to November, in which the south-east trade winds blow. The average daily temperature goes from around 27 °C (81 °F) in the warmest period (January to April), to around 23 °C (73 °F) in the coolest months (July, August and September).
Here are the average temperatures of Moroni.
Average temperatures - Moroni

Moroni	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Moroni	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	23	23	23	23	21	20	19	18	19	20	22	23
Max (°C)	30	30	31	30	30	28	28	28	28	29	30	31
Min (°F)	73	73	73	73	70	68	66	64	66	68	72	73
Max (°F)	86	86	88	86	86	82	82	82	82	84	86	88

Of the three main islands that make up the archipelago, the two smaller ones (Mohéli and Anjouan) are covered by hills in the interior, while the largest, Grande Comore or Ngazidja, is home to a real mountain, the volcano Karthala, 2,360 metres (7,743 feet) high. The slopes enhance cloud formation, which can bring showers and thunderstorms, especially on the main island, which in fact is the rainiest. On Mount Karthala, even 5,000 millimetres (195 inches) of rain per year fall, while the capital Moroni, which in the rainy season is located on the windward side (that is, it's exposed to the north-west monsoon), receives 2,700 mm (106 in) of rain per year.
Here is the average precipitation in Moroni.
Average precipitation - Moroni

Moroni	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Moroni	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	365	295	280	315	255	265	245	150	110	95	110	220	2705
Prec.(in)	14.4	11.6	11	12.4	10	10.4	9.6	5.9	4.3	3.7	4.3	8.7	106.5
Days	18	16	18	18	12	12	12	10	11	12	12	16	167

In Fomboni, in the island of Mohéli, the total annual rainfall is 2,100 mm (83 in). Ouani, in the island of Anjouan (also known as Nzwani), receives 1,800 mm (70 in) of rain per year. January is the rainiest month throughout the archipelago, with more than 300 mm (12 in) of rain along the coasts, while the driest month in Moroni is October, with 95 mm (3.7 in) of rain, which shows that there's no shortage of showers and thunderstorms even in the dry season, at least in the main island. However, these rains, though intense, are short-lived, so that they soon make room for the sun. In the smaller islands, during the dry season, showers are less frequent and less intense.
Here is the average precipitation in Fomboni.
Average precipitation - Fomboni

Fomboni	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Fomboni	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	330	280	245	240	180	145	155	105	60	90	95	195	2115
Prec.(in)	13	11	9.6	9.4	7.1	5.7	6.1	4.1	2.4	3.5	3.7	7.7	83.3
Days	17	15	16	13	12	10	10	7	4	6	7	13	130

Despite the rains, due to the absence of rivers, the Comoros suffer from a shortage of fresh water.
The Comoros are located in the path of tropical cyclones, which can pass over the islands from November to mid-May, with a greater chance from late December to mid-April.



The amount of sunshine in the Comoros is never exceptional, nor scarce. The sun shines for a few hours a day even in the wettest months; the sunniest period is that of the trade winds, May-November, in which however some cloudiness can form, especially near the mountains.
Sunshine - Moroni

Moroni	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Moroni	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	6	6	7	6	7	8	8	7	7	8	8	7

The sea in the Comoros is warm enough for swimming all year round: the water temperature ranges from 25 °C (77 °F) in August, to 29 °C (84 °F) in the period from February to April.
Sea temperature - Moroni

Moroni	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Moroni	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	29	29	29	29	28	27	26	25	26	26	27	28
Sea (°F)	84	84	84	84	82	81	79	77	79	79	81	82

The best time to visit the Comoros and enjoy their yet uncrowded beaches, runs from June to October: it's the least sultry, the driest and sunniest, although some showers must still be put into account, especially in the main island. In the latter, given that the rains are still abundant in June and July, you can choose the period from August to October.


In winter (June to August): light clothes, a sweatshirt for the evening, a light scarf for the breeze; for the reef, equipment for snorkeling, water shoes or rubber soled shoes. For women, it is best to avoid shorts and miniskirts outside of tourist resorts. To climb Mount Karthala, hiking boots, fleece, raincoat.

In summer (December to February): tropics-friendly, loose fitting clothing, light shirts and pants of natural fibres (cotton, linen) or synthetics that breathe, light sweatshirt for the evening, light raincoat or umbrella.