Climate & Tides
Fiji enjoys a tropical maritime climate without great extremes of heat or cold.
At all seasons the predominant winds over Fiji are the trade winds from the east to the south-east. On the coast of both main islands Viti Levu and Vanua Levu, day time sea breezes blow across with great regularity.
In general, the winds over Fiji are light or moderate; strong winds are uncommon and are most likely to occur through channels and around the headlands in the period June to November when the trade winds are most persistent.
Air & Water Temperatures
Temperatures at the lower levels around Fiji are fairly uncommon. In the lee of the mountains, however, on the western and northern sides of the main islands (including Taveuni), the day-time temperatures often rise 1 to 2C (35-36F) above those on the windward sides or on the smaller islands. Also, the humidity on the lee side tends to be somewhat lower.
Due to the influence of the surrounding ocean, the changes in the temperature from day to day and season to season are relatively small. The average temperatures change only about 2 to 4C (36-39F) between the coolest months (July and August) and the warmest months (January and February). Around the coast, the average night-time temperatures can be as low as 18 to 20C (64-68F) and the average day-time temperatures can be as high as 30 to 32C (86-90F). South-eastern coastal areas and the high interior often experience persistent cloudy humid weather.
The water temperature in Fiji fluctuates very little (average around 26C/ 79F) making it’s crystal blue waters perfect for year round snorkelling and other water activities.
Tides in Fiji
One of the first things you will notice about our coastal waters in Fiji are our tides.
Tides are natural predictable events that vary in strength on a regular basis. They result from various different forces or combination of forces caused by the movement of the moon and sun relative to the earth.
Normal tidal movement can also be influenced and exaggerated due to movement of the Earth’s crust (earthquakes) that produce Tsunamis and intense weather conditions that cause storm surges and severe waves which occur during cyclones.
Spring tides produce higher high tides and lower low tides and occur every 14 days at the time of the full moon and new moon when the sun, the moon and Earth line up to exert the maximum gravitational force at the Earth’s surface.
Neap tides on the other hand are tides of smaller variation ie lower high tides and higher low tides. These occur during the first and third quarters of the moon when the position of the moon and the sun form a right angle to the earth. Variations in the magnitude of the spring and neap tides occur partly because of the changes in the position of the moon and sun relative to the Earth, and the orbit of the moon around the Earth and the Earth around the sun.
Tides in Fiji are generally diurnal, lower low water spring tides fall during the night in summer and this is reversed in the winter, falling during the day with the seasonal change. The annual mean tidal range is very small at 1.1m (3.6ft). The mean range of neap tides is 0.9m (2.9ft) and spring tides reach an amplitude of 1.3m (4.2ft).
Rainfall is highly variable and mainly orographic (influenced by the island topography and the prevailing south-east trades). The south-east trade winds are saturated with moisture, any high land mass lying in their path receives much of the precipitation. The mountains of Viti Levu and Vanua Levu create wet climatic zones on their windward sides and dry climatic zones on their leeward sides, hence, the main islands have pronounced dry and wet zones. Little climatic differentiation occurs on the smaller islands having low relief.
Fiji experiences a distinct wet season (December to April) and a dry season, controlled largely by the north and south movements of the South Pacific Convergence Zone, the main rainfall producing system for the region. Much of Fiji’s rain however falls in heavy brief local showers. Rainfall is usually abundant during the wet season (December to April), especially over the larger islands, and it is often deficient during the rest of the year, particularly in the ‘dry zone’ on the north-western sides of the main islands. In the drier half year, from May to October, the heaviest rainfall occurs on the windward (south-east) parts of the larger islands. Annual rainfall in the dry zones averages around 2000mm, whereas in the wet zones, it ranges from 3000mm around the coast to 6000mm on the mountainous sites. The smaller islands receive amounts intermediate between those on the wet and dry sides of the larger islands.
The south-eastern parts of main islands, generally receive monthly total rainfall of 150mm during the dry season and 400mm during the wettest months. These parts of the islands have rain on about six out of ten days for the dry season and about eight out of ten days in wet season. The north-western parts of these islands are in the rain shadow and receive generally less then 100mm per month during the dry period. The variation in the monthly totals between the two zones during the wet season is little. The wettest month is usually March and the driest month is almost always July. During the wet season, brief heavy afternoon showers and thunderstorms are common.
Fiji experiences prolonged dry spells quite often, usually for three to four months duration, when the north-western parts of the main islands receive little or no rain. The ENSO (El Nino Southern Oscillation) phenomenon appears to be a major contribution to the fluctuations of climate, especially rainfall in the South Pacific. It has been seen that during most of the ENSO episodes, the rainfalls are extremely low in the dry zones.
Due to the great variability of rainfall in the region, averages have little value as indicators of what the rainfall is likely to be in any particular month or season.