Fortunate for visitors enjoying the sun, and unfortunate for local farmers, the Turks and Caicos receives little rainfall.
Based on a 10 year sample of data between 2006 and 2016, the average number of days with rain each year in Providenciales is 43, or about every 8.5 days. However, much of this rainfall is clustered in the rainy season from May to November. The chart below uses data from 2012-2015.
Rainfall patterns according to region are quite observable in the Turks and Caicos, and as a small tropical country consisting of islands of limited landmass, precipitation is predictably low.
The extensive marine wetland flats on the south sides of East Caicos, Middle Caicos, and North Caicos largely account for this. Consisting of dark saline mud and grey marine limestone, the groundcover on the flats retains quite a bit of the sun’s intense heat, and this in turn warms the surrounding humid air. As the air rises, it condenses into rain at the cooler and higher altitudes. Due to the constant east southeast trade wind patterns, this rain typically falls on and to the north of North Caicos, and on the small nearby cays.
When it occurs, this rain usually falls a few hours after midday, and by late afternoon the conditions will often be clear and sunny.
Although not quite as predictable due to its smaller scale, the central west coast region of Providenciales also experiences predictable precipitation. Along with several fresh water ponds, trees that are larger than what is typical to the island are found here including the sabal palm, West Indian mahogany, and buccaneer palm.
The small islands of Grand Turk and Salt Cay, located on the far eastern edge of the Turks and Caicos, don’t have the advantage of geography that the Caicos Islands have and are consequently see far less rainfall.
Although annual rainfall in the Turks and Caicos is one of the lowest in the region, flooding does occur at times, and is largely confined to few distinct areas in the country.
Generally a by-product of tropical depressions during the summer and autumn hurricane season, such floods often result in quite significant rainfall over a short period of time. In some cases, areas may experience more than a third of their expected annual rainfall over a matter of days.
Due to the marine limestone geomorphology of the country, the low rolling hills and small valleys of the interiors of the larger islands can hold water for weeks, however, natural drainage routes and Karst features typically reduce the duration of flooding.
Regions near the ocean, where much of the development in the country is located, usually have either direct natural drainage to the ocean, or have porous sandy ground which doesn’t hold water.
Several populated areas in the Turks and Caicos are at risk of flood, although floods solely from precipitation are more of an inconvenience for road travel rather than an actual danger.
Mud slides and flash floods, the events resulting rainfall which typically account for the most lives taken during flooding in other regions, are not experienced in the Turks and Caicos due to our small islands and low rocky terrain.
Downtown, The Bight, and Five Cays on Providenciales will typically experience flooding in roads and low elevations of up to one to two feet in (.3 to .6 meters) depth. The small settlement of Kew on North Caicos usually sees the worst, will some low points near the village seeing more than 10 feet (3 meters) of standing water.
Due to the very low elevation of much of the settlements and development in the Turks and Caicos, flooding from hurricane storm surges is a real and far greater danger, with the potential for widespread destruction.
The Turks and Caicos hasn’t experienced a major hurricane since Hurricane Donna in 1960. Although winds speeds were not comparatively significant and the storm’s path wasn’t particularly close to the country, the surge from the 2015 Hurricane Joaquin was one of the highest seen in decades. A direct hit by a major storm could cause catastrophic flooding.
After heavy rains, mosquitoes will often be a problem on the larger Caicos Islands. Due to the prevailing breeze, Providenciales typically only sees this increase for a couple weeks, however the problem on North Caicos, Middle Caicos and Pine Cay often persists for quite a bit longer.