Fiji, an archipelago in the Pacific Ocean, located north of the Tropic of Capricorn, has a tropical climate, with a hot, humid and rainy season from December to April, and a cooler season from June to October.
The cool season is relatively dry, especially in the small and flat islands, and in the north-western slopes of the main islands (Viti Levu and Vanua Levu), while in the slopes exposed to the south-east, the trade winds can cause showers and thunderstorms even in this season. In the following image we can see in a schematic way the south-east trade winds which blowing in the cool season, which are cool and humid in the exposed sides, and warmer and drier in the downwind sides.



For example, in Suva, located in the south-eastern side of the island of Viti Levu, and therefore exposed to the trade winds, even 2,900 millimetres (114 inches) of rain per year fall, of which more than 270 mm (10.6 in) per month from December to April, when it rains more than one day out of two, however, it still rains on average around every second day in the least rainy months, with a minimum of 120 mm (4.7 in) in July. Therefore, here we can speak of equatorial climate, because there is no dry season. Here is the average precipitation.
Average precipitation - Suva

Suva	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Suva	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	280	270	360	300	250	170	120	210	190	210	240	310	2910
Prec.(in)	11	10.6	14.2	11.8	9.8	6.7	4.7	8.3	7.5	8.3	9.4	12.2	114.6
Days	18	18	21	19	16	13	14	15	16	15	15	18	198

The daytime temperature in the capital Suva, around 30 °C (86 °F) from January to March, drops to 26/27 °C (79/81 °F) from May to October; even night-time temperatures drop slightly, from 23 °C to 20 °C (73 °F to 68 °F). However, in the coolest months, sometimes at night the temperature can go down to 12/13 °C (54/55 °F), so it can get quite cool.
Here are the average temperatures.
Average temperatures - Suva

Suva	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Suva	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	23	23	23	22	21	20	20	20	20	21	21	22
Max (°C)	30	30	30	28	27	26	26	26	26	27	28	29
Min (°F)	73	73	73	72	70	68	68	68	68	70	70	72
Max (°F)	86	86	86	82	81	79	79	79	79	81	82	84

In Suva there are not many sunshine hours, because clouds can be formed all year round.
Sunshine - Suva

Suva	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Suva	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	7	6	6	5	6	6	6	5	5	6	6	6

The sea temperature decreases a bit in the winter months, although it remains pleasantly warm for swimming, as can be seen in the following table.
Sea temperature - Suva

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

In Nadi, on the western slope of the same island of Viti Levu, rainfall is much lower, 2,050 mm (80.5 in) per year, and while it rains a lot in the rainy season, from December to April, it rains much less from May to October, when precipitation drops below 100 mm (4 in) per month; the driest month is June, with 55 mm (2.2 in) of rain. The rainy days are fewer as well: 7/8 days per month from July to October, and 10 per month in May and June. Here is the average precipitation.
Average precipitation - Nadi

Nadi	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Nadi	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	305	295	420	220	105	105	55	65	85	60	130	210	2055
Prec.(in)	12	11.6	16.5	8.7	4.1	4.1	2.2	2.6	3.3	2.4	5.1	8.3	80.9
Days	16	16	19	15	10	10	7	7	8	8	11	12	139

On the contrary, on the western side the temperature is a little higher, because the winds blow from the inland hills, especially in the coolest months, when the maximum temperature is around 28 °C (82 °F), instead of 26 °C (79 °F).
Average temperatures - Nadi

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

The amount of sunshine too is higher in the leeward side than in the windward side: about 7/8 hours per day in Nadi, compared to the 5/6 hours of Suva.
Sunshine - Nadi

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

These differences between the two sides are also found in the other main island, Vanua Levu. In the smaller islands, especially the flat ones, the difference is smaller, because the trade winds do not find hills upon which they could discharge moisture on one side, so that these islands receive about 1,700/1,800 mm (67/71 in) of rain per year, with a minimum in the coolest months.



An exception is represented by the island of Rotuma, because it is located far to the north, and is very rainy because of the latitude: with its 3,500 mm (138 in) of rain per year, it has an equatorial climate, with a minimum from June to September, when around 200 mm (8 in) of rain per month fall anyway. Here is the average precipitation.
Average precipitation - Rotuma

Rotuma	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Rotuma	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	340	325	330	265	275	220	205	190	190	280	285	305	3210
Prec.(in)	13.4	12.8	13	10.4	10.8	8.7	8.1	7.5	7.5	11	11.2	12	126.4
Days	18	18	20	19	19	19	20	19	18	18	17	16	221

This island is also warmer, especially in winter, which in fact does not exist, and therefore has stable temperatures throughout the year, as we can see from its average temperatures.
Average temperatures - Rotuma

Rotuma	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Rotuma	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	24	25	24	24	24	24	24	24	24	24	24	24
Max (°C)	31	31	31	31	31	30	30	30	30	30	31	31
Min (°F)	75	77	75	75	75	75	75	75	75	75	75	75
Max (°F)	88	88	88	88	88	86	86	86	86	86	88	88

In Rotuma, the temperature of the sea remains high throughout the year as well, as can be seen in the following table.
Sea temperature - Rotuma

Rotuma	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Rotuma	J	F	M	A	M	J	J	A	S	O	N	D
Sea (°C)	29	29	29	29	29	28	28	28	28	28	29	29
Sea (°F)	84	84	84	84	84	82	82	82	82	82	84	84

Fiji can be affected by tropical cyclones. Cyclones are usually formed from November to mid-May, though they are most likely from late December to early April. Outside of this period, there has been cyclone Bebe, which passed in the second half of October 1972). One more reason to avoid the muggy and rainy season.

In addition, the Fiji Islands are affected by the climate cycle called ENSO: during the more intense years of El Niño, such as 1983 and 1998, they experienced a noticeable decrease in precipitation.


The best time to visit Fiji is from mid-May to mid-October: it's the most dry, cool and sunny, especially in the north-western slopes of the main islands, which are preferable also because they are more sheltered from the wind.


In winter (June to August): light clothes for the day, a scarf for the breeze, a sweatshirt for the evening; light raincoat or umbrella. For the reef, equipment for snorkeling, water shoes or rubber soled shoes.
In summer (December to February): light clothes, of natural fibres, sun hat, a scarf for the breeze, a light sweatshirt for the evening; light raincoat or umbrella.
In Rotuma, all year round, light clothing, of natural fibres, sun hat, a scarf for the breeze, a light sweatshirt for the evening, light raincoat or umbrella.