CLIMATE OF ST. LUCIA
The island of St. Lucia lies near 14 degrees north latitude and 61 degrees west longitude
or about 5000 kilometres west of the West African coast. It is part of the Eastern Caribbean
archipelago. Neighbouring islands are Martinique 24 miles to the north , St. Vincent 21 miles to
the south and Barbados 100 miles to the southeast. St. Lucia is of volcanic origin and occupies an area of 238 square miles. The
interior is rugged and mountainous but there several coastal and river
valleys. The island lies within the northeast Trade Wind belt and enjoys a
tropical maritime climate.
St. Lucia experiences one wet and one dry season annually. The rainy(wet)
season runs roughly from June to December and the dry season from February to
May. January is a transition month and may be wet or dry. Average total annual
rainfall is about 1700 millimetres with September being the rainiest month.
Rainfall is significantly higher over the mountainous interior than coastal
areas due to orographic effects. The northernmost and southernmost areas of the
island are the driest. Heaviest rainfall comes from tropical cyclones ,
tropical waves, the Inter Tropical Convergence Zone and Upper Level troughs.
Some of the outstanding rainfall events on record are:
- the passage of tropical storm
Debby on 10 September, 1994.
- the passage of a tropical wave on
26 October, 1996.
- a convective flare-up associated
with a deep layered trough on 21 February, 2000.
Widespread
flooding and substantial damage to infrastructure
resulted from all the above events.
Ambient air
temperature in open spaces rarely reach above 34 degrees Celsius / 93 degrees
Fahrenheit or fall below 22 degrees Celsius / 72 degrees Fahrenheit. The mean
temperature is near 28 degrees Celsius or 82 degrees Fahrenheit.
Diurnal(daytime vs. night-time ) variation is of the order of 6 degrees Celsius
whereas seasonal variation is near 2 degrees Celsius. The coolest months are from December to March
and the warmest from August to October. Average maximum temperature is near 30
degrees Celsius/86 degrees Fahrenheit and average minimum near 25 degrees
Celsius/77 degrees Fahrenheit.
Winds are
generally out of the east between 070 degrees and 100 degrees at an average
speed of about 16 m.p.h. The windiest months are from January to July. St.
Lucia lies in the hurricane belt and may be affected by tropical cyclones with
very strong winds. The most significant wind event on record occurred with the
passage of hurricane Allen on the night of 04 August, 1980. Widespread damage
to infrastructure and an almost total lost of the banana crop resulted from
this event.
Detailed
statistics on rainfall, wind speed and direction, temperatures, soil
temperature, evaporation, sunshine duration, etc. are available from the St.
Lucia Met. Service. Address queries to:
slumet@hotmail.com
climo@slumet.gov.lc