Saint Kitts & Nevis - Climate

Both St. Kitts and Nevis have a tropical climate tempered by the northeast trade winds; there is little daily or seasonal variation. Temperatures generally range between 18°C and 32°C and average approximately 26°C; lower temperatures prevail in the higher elevations. Humidity is generally about 70 percent. Annual precipitation varies from 100 to 300 centimeters. Neither island has the distinct rainy season characteristic of many other Caribbean islands. Winds are predominantly easterly and seldom exceed nineteen kilometers per hour except during the islands' hurricane season, which occurs from July to September.

The hurricane season in the Caribbean normally runs from June to November. Saint Kitts and Nevis is susceptible to hurricanes. Hurricanes Omar and Earl affected the country in 2008 and 2010, respectively. Omar caused damage to the Four Seasons Resort, the largest tourism resort on Nevis, which remained closed for two years, resulting in 600 job layoffs on an island of 12,000 persons. Omar’s impact on the country’s balance of payments was estimated at US$ 19 million — about 3.5% of GDP. Disaster plans have been developed and training in disaster management was conducted for Ministry of Health first responders, nurses and physicians and staff from the disaster management department, the Red Cross, and the Defense Force.

The volcanic highlands of the three Windwards, all with generally north-south axes, also represented orographic barriers lying at right angles to the prevailing winds, thereby forcing the moisture-laden air to ascend, cool adiabatically and reduce its ability to hold water vapour; the resulting heavy rains at the high elevations, which contrasted sharply with Barbados' drought prone lowlands.

The majority of the islands’ inhabitants live near the coastline, as the interior tends to be extremely rugged and steep. However, pressure for agricultural land has caused small farmers to clear forested plots along slopes for farming, causing deforestation, soil erosion and water pollution.

The country is vulnerable to the impacts of climate change, such as increased sea level, rising ocean temperatures, and stronger hurricanes. Saint Kitts and Nevis ratified the Kyoto Protocol to the United Nations Framework Convention on Climate Change in 2007 and cooperates with other countries in the Caribbean in adaptation to climate change.

The islands’ coasts may be exposed to sea-level rise and other impacts of climate change, including a worsening of present trends of coastal erosion, saline intrusion and sea flooding. These processes could negatively impact natural resources (including coral reefs) and infrastructure.

In Saint Kitts and Nevis water resources are vulnerable to sea level rise and temperature increase leading to higher evaporation rates. Given the centrality of ground water sources to the national water supply, the problem of water resources is primarily one of keeping and protecting the underground water resources. Given the islands’ dependence on groundwater and anticipated decreases in precipitation in the Caribbean region, water availability on the island may become scarcer and prone to saline intrusion. These impacts would spillover to other sectors of the economy and society, including agriculture, health and tourism.

Adaptation measures would include the following actions: Rational use of available water enforced by the national water authority; Controlled rate of pumping from aquifers; Conservation of protective forests that allows a high rate of infiltration of rainfall to the aquifers; and Protection of contamination of underground water from pollution sources - agricultural, human settlements and others. The use of measures for minimizing runoff of freshwater to the ocean environment would have to be done in agreement with the requirements of the coastal ecosystems, which thrive on definite levels of salinity and organic sediments from land areas.

Adaptation options for the tourism sector include: Developing and enforcing environmental policies and regulations (including building regulations) for tourism activities that take into account the issues of sea level rise and climate change; Ensuring that the risks associated with sea level rise (coastal flooding, increased action of waves and coastal erosion, enhanced storm surges and rising water tables) are taken into consideration in the building and development of new tourism resorts; Redirecting tourism from activities that adversely impact on natural fragile ecosystems, toward more societal activities of historical, traditional and cultural nature that will not be associated with climate change issues.