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Weather in
French Polynesia
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Tahiti and her islands, the sunny paradise !
French Polynesia is a tropical destination
with lots of sun all year through and just
enough rain for its luxuriant vegetation and
its colourful flowers.
The
islands enjoy a tropical climate which is
always pleasant and is cooled by the trade
winds of the Pacific that blow throughout the
year.
The average
temperature is 27°C / 76°F
and the waters of the lagoons are a fairly
constant 26°C. Further away from the equator,
the archipelagos down south (the Australs &
Gambier) have cooler temperatures |
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Polynesia receives
in average 2,500 to 2,900 hours of sunshine per
year. (ie : 8 hours of sun per day). Temperatures
range between 24°C and 30°C all year through and
lagoon water temperature varies between 23°C and
26°C.
Thus, the climate of Polynesia -defined as marine
tropical- is hot (average air temperature is
26.5°C) and humid (hygrometry : 75%) but tempered
by the ocean. Thus, Polynesia is submitted to
northeast and southeast trade winds converging to
the equatorial zone which creates two distinguished
seasons : the dry season and the humid season.
The dry season -also
called Austral winter- taking place between April
and October brings an expected coolness, July and
August being the coolest months of the year due to
southeast trade winds called maraamu. As a
consequence a cotton sweater will often be
enjoyable in the evening (or early in the
morning).
The humid season
-also called Rainy season- starts in November and
ends in March. It brings mugginess, humidity as
well as heavier and more frequent rains than in
the dry season. During that season, tropical
storms may occur. Winds can reach speeds of over
220 km/h and can eventually evolve to a cyclone,
an extremely rare event though. French Polynesia
was touched lastly by cyclones at the beginning of
the 90’s after having been hit 6 consecutives
times in 1982-1983 (this has not happened since 1906
!). These cyclonic events are due to a well know
phenomenon called “El Nino” (see below for more
details).
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El Nino
This phenomenon has been studied by meteorologists
for many years and it is well-known for its
unpleasant consequences and more specifically for
its role in the development of cyclones and
hurricanes.
Actually, El Nino is a periodical marine draft
whose activity is not considered abnormal since it
has been active for the past 5,000 years. What is
abnormal is its high frequency in the latest
years. It usually appears around Christmas time
(that is why it has been named El Nino – the
Child). It occurred in 1972/73, 1975/76, 1982/83,
1986/87, 1991/92 and 1997/98 (the strongest of the
century). Using the effects of trade winds, El
Nino is responsible for bringing down along the
coasts – from western to eastern Pacific - hot
waters of equatorial regions.
Normally, trade winds make high pressure
subtropical air to converge towards equatorial low
pressure regions, drawing along with them hot
ocean waters from East to West. But when those
trade winds weaken, they reverse (change around)
and consequently they draw with them those same
hot water from West to East. This constitutes el
phenomenon called “El Nino”.
In eastern Pacific, water temperatures are usually
below 25°C. Those hot water currents make the
average ocean water temperatures to increase by 3
to 4°C. This increase generates a succession of
climatic anomalies, characterized in Polynesia by
trade winds inversion and sometimes the birth of a
cyclone when the ocean temperature is over 28°C.
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