• Frequent episodes of Saharan dust incursions into the Caribbean in the coming season may increase the risk of exacerbations of allergic rhinitis and asthma in susceptible persons. In the areas where ongoing short term drought is expected to subside (i.e., Barbados, St. Kitts and many of the Windward Islands), there may still be relatively high atmospheric dust concentrations, as well as, potential soot and smoke from bushfires until the wet season rains moisten the topsoil. Such conditions may initially contribute to higher concentrations of airborne particulate matter. This could result in an increase in acute respiratory illnesses, as well as ocular allergies.
• The increased soil moisture and humidity towards the end of July in the northern and eastern parts of the Guianas, as well as, in Belize and the Caribbean Islands towards the end of August may promote mold growth in damp and poorly ventilated buildings, leading to increased respiratory symptoms. Given that rain showers should be less frequent this year, mold growth between June and August is less of a concern than in some recent years.

• Following extreme weather events or disasters, there is an increased chance that the conventional means of water supply may be compromised resulting in persons seeking alternative water resources where the water is untreated and the water quality is unknown. This has the potential to increase the risk of gastrointestinal illness.
• Where episodes of flooding may occur, cases of gastroenteritis may increase, where persons consume foods contaminated by these waters. This is increasingly the case across Belize and the Caribbean islands towards the end of August. By contrast, the likelihood decreases in the Guianas after July. The ABC Islands are usually spared of flooding, unless they are impacted by tropical cyclones.
• Where short-term drought conditions are currently in place (i.e., Barbados, St. Kitts and many areas in the Windward Islands), and/or where those drought conditions may persist through August, concentrations of water pollutants in small reservoirs and tanks may temporarily increase. Additionally, in some cases, a reduction in water pressure in distribution systems may result in cross-contamination and use of alternative, unsafe sources, in turn potentially causing higher incidences of gastrointestinal illness.

• Levels of morbidity and the rate of hospitalisations due to the effects of excessive heat are likely to increase in view of high temperatures and increasing humidity – especially during hot spells – across the region towards August.
• Throughout the three-month period, there will be increased risk of heat stress (particularly in northern parts of the Caribbean) which may present as a worsening in chronic conditions such as cardiovascular, respiratory, cerebrovascular disease and diabetes-related conditions. Symptoms can include lethargy, general weakness, dizziness, fainting and, in extreme cases, kidney failure. For information on heat and health see: https://www.who.int/health-topics/heatwaves#tab=tab_1 and https://ghhin.org/
• Throughout this period, the UV index on sunny days will be 11-12 (extremely high). Excessive exposure to dangerous UV radiation can cause skin damage in persons who spend extended periods outdoors, especially on sunny days (for more information, see: https://www.epa.gov/sunsafety/uv-index-scale-0). For simple action steps on sun protection see: https://www.who.int/news-room/questions-and-answers/item/radiation-the-ultraviolet-(uv)-index
• There is the increasing possibility of skin infections due to contact with contaminated stagnant and/or flood waters. With the increasing shower activity along the wet season, the risk increases across Belize and the Caribbean islands from June to August. However, the transition from wet to dry season in early August in the Guianas means a decrease in likelihood after July in those areas. The risk is low in the ABC Islands, which are in their long dry season.

• Episodes of flooding may occur in any area of the Caribbean during this period. In such cases, there is increased risk of Leptospirosis due to displaced rodents that could contaminate flood waters, household items and food containers. The risk is higher in eastern parts of the Guianas.
• The presence of stagnant water in the aftermath of a flood may promote the breeding of mosquitoes. However, note that in the case of flash floods, flood waters may sweep away mosquito eggs, larvae and pupae, potentially reducing mosquito populations for up to a few weeks after flash flooding.
• In the few areas where there is lingering drought (especially in St. Kitts, Saint Lucia and St. Vincent) or where dry spells remain frequent during this period (i.e., primarily in the Greater Antilles), there may be increased use of containers for storage. This may potentially create more breeding sites for mosquitoes, especially those associated with diseases, such as Dengue, Chikungunya and Zika. In addition, higher temperatures increase the rate of development of mosquito vectors and mosquito populations, as well as increase the risk of transmission of vector borne diseases. Unseasonably high temperatures in northern parts of the Caribbean (i.e., north and west of Dominica) may lead to a higher risk than areas further south where temperatures are forecast to be only slightly higher than usual. Proper management of water storage containers e.g., covering with protective mesh helps to reduce this risk.
• Access useful materials on mosquito control measures here: (https://www.paho.org/en/campaigns/caribbean-mosquito-awareness-week-2020); Join the fight against mosquito borne disease in the Caribbean: https://carpha.org/What-We-Do/Public-Health/Dengue and http://missionmosquito.carpha.org/

• Severe weather systems, which can come with a range of hazards, including high winds, landslides, flash floods, among others, are expected to affect Caribbean territories, potentially in rapid succession. With the possibility of severe weather systems such as tropical cyclones, health practitioners and administrators should maintain a state of readiness.
• During episodes of extreme heat, severe weather events or disasters, vulnerable populations may have an increased need for medical care as they face a greater risk of reduced well-being, poor health or possible mortality. Health care providers and other stakeholders should clearly define and locate populations in situations of vulnerability or persons who are intrinsically more vulnerable, and develop tailored strategies for assisting them.
• Peaks in heat stress associated with extreme heat, can increase mood-affective and stress-related disorders, as well as, other mental and behavioural disorders. This is especially of concern in the northern parts of the Caribbean where a strong increase in heat waves compared to most years is forecast. Persons taking medication for mental health disorders are at greater risk of heat-health effects.
• Frequent hot spells in the upcoming period are highly likely to increase exhaustion during intense outdoor activity and limit labour productivity. They can further increase sweating and water consumption and, during prolonged heat waves (i.e., when extreme heat is sustained during several successive days and nights), lead to fatigue, irritability and aggression.
• When disasters have seasonal patterns, like hurricanes, floods and drought, psychosocial impacts such as anxiety among survivors may increase as alerts on hazardous events arise. Health care professionals are therefore advised to be sensitive to these issues, as they interact with patients.

This Bulletin provides a broad overview of climate conditions up to 3 months in advance. It is based on insights drawn from CIMH’s suite of technical climate information products and epidemiological insights from CARPHA and PAHO. The information contained herein is provided with the understanding that the CARPHA, the PAHO and the CIMH make no warranties, either expressed or implied, concerning the accuracy, completeness, reliability or suitability of said information. The Bulletin may be freely used and disseminated by the public with appropriate acknowledgement of its source but shall not be modified in content and then presented as original material.