• The increasing dryness of soils in March may be compounded by short term drought in a number of locations across the region. The associated increase in dust, as well as, potential soot and smoke from wildfires may contribute to higher concentrations of airborne particulate matter. This could result in an increase in acute respiratory illnesses. The level of concern should decrease by the end of May with the expected occurrence of significant rainfall events in April or May.
• There may be an increase in symptoms in persons with chronic respiratory conditions such as asthma, and in persons prone to allergic rhinitis due to more frequent episodes of Saharan dust incursions into the Caribbean, as well as due to local dust being suspended in the air when the ground surface is dry.
• This may be offset by a decrease in allergic reactions to fungal spores from mould at least until the end of March. By contrast, increasing humidity across the region from April onwards could cause dampness in some poorly ventilated residences and offices resulting in the growth of mould. In the Caribbean islands, increased allergens in the atmosphere may occur from plant materials (e.g., pollen) driven by increased wind speeds. These factors may also trigger more frequent occurrence of upper respiratory tract symptoms.
• Increasing humidity towards May in the Bahamas, Belize, the Greater Antilles and the Guianas as these areas transition into the Wet Season may promote mould growth in damp and poorly ventilated buildings, leading to increased allergic reactions.
• There is an increased risk of ear, nose, and throat infections from contact with contaminated water where episodes of flooding may occur, particularly in April and May.

• Ongoing dryness and drought conditions may increase concentrations of water pollutants. Additionally, a drop in water pressure in potable water supply systems may result in cross contamination and reduced access to water. Alternative use of unsafe sources of water, in turn may potentially contribute to higher incidences of gastrointestinal illness.
• Cases of gastroenteritis may increase in frequency due to contamination of food and water supplies, and contact with flood waters across the region from April onwards.

• Higher temperatures and the occurrence of heat waves begin in April across the region, with the likely exception of the Guianas. This can increase the risk of morbidity from heat-related health effects, resulting in a possible increase in hospitalisations and emergency room visits. Such effects may include apathy, general weakness, dizziness, fainting, exhaustion (heat strain) and, in extreme cases, lead to kidney failure. These effects may be exacerbated in persons with chronic illness, children, pregnant women, the elderly and persons who may not find appropriate shelter from the heat. For information on heat and health see: https://www.who.int/health-topics/heatwaves#tab=tab_1 and https://ghhin.org/
• During this period, excessive exposure due to dangerous UV radiation can cause skin damage in persons who spend extended periods outdoors, especially on sunny days, if unprotected (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 floodwaters in the region from April onwards.

• Increased rainfall and the more frequent occurrence of stagnant water from flooding from April onwards – particularly in the Guianas – may create more breeding sites for the Aedes aegypti and Aedes albopictus mosquitoes which are the vectors of diseases such as Dengue, Chikungunya, Zika and Yellow Fever. These diseases remain a perennial concern for Caribbean territories.
• With increasing dryness and recurrent dry spells across the region in March, and, in some locations, going into April, there may be increased use of containers for water storage. This may be further exacerbated in Cuba, French Guiana, southern Puerto Rico, and other areas where drought is evolving.
• At the household level, careful attention should be given to the management of water storage containers. This includes mosquito proofing water tanks, barrels, drums and buckets.
• In May – or, possibly, even in April -, the presence of stagnant water in the aftermath of a flood may promote the breeding of mosquitoes. The highest likelihood would be in the Guianas. However, note that in the case of flash floods, flood waters may sweep away mosquito eggs, larvae and pupae, potentially reducing mosquito populations in the short term.
• The focus should be on public education and awareness on source reduction and personal protection. If fogging operations are considered by a country’s Ministry of Health, advice should be sought from the local meteorological services on temperature, wind speed, humidity, etc.
• Access useful materials on mosquito control measures here: https://www.paho.org/en/topics/vectors-integrated-management-and-public-health-entomology; Join the fight against mosquito borne disease in the Caribbean: https://carpha.org/What-We-Do/Public-Health/Dengue and http://missionmosquito.carpha.org/
• Flooding may increase the risk of Leptospirosis due to displacement of rodent vectors from their usual habitats into houses, increasing the risk of contamination of slow moving or stagnant waters, household surfaces and food-stores with rodent urine.

• Severe weather systems, which can come with a range of hazards, including high winds, landslides, flash floods, among others, may possibly affect Caribbean territories. With the possibility of tropical cyclones before the official start of the 2025 Atlantic Hurricane Season, health practitioners and administrators should maintain a state of readiness.
• Food insecurity and associated possible undernutrition would be a concern due to the potential for extensive crop damage and/or loss associated with frequent dry spells across the region. This may be exacerbated in areas where drought is evolving. A similar concern arises as a result of the high flood potential in the Guianas in April or May.
• The occurrence of heatwaves in April or May, and possibly as early as March in some locations, may increase exhaustion during intense outdoor activity and tends to limit labour productivity. It can further increase sweating and water consumption and, during prolonged heatwaves, lead to fatigue, irritability and aggression.
• Mental health effects may increase due to extreme weather events, their impacts and associated alerts. Health Care Professionals are therefore advised to be aware of 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.