By 2050, St. Maarten could see 136 hot days, less rain and 22cm of sea-level rise

GREAT BAY--A new climate report projects that St. Maarten could experience as many as 249 hot days each year (exceeding 29.5 degrees Celsius) by the end of this century under a high-emissions scenario, while annual rainfall could decline by nearly half and sea levels rise by up to 78 centimeters. Even earlier than that, by 2050, St. Maarten could See 136 hot days and 22 centimeters of sea-level rise.

The findings are contained in the newly released Climate Scenarios for St. Maarten report, which examines how temperature, rainfall, wind and sea level could change by 2050 and 2100 under six possible climate scenarios. By Comparison, St. Maarten currently experiences an average of 17 hot days per year, defined in the report as days when the average temperature, including both daytime and nighttime readings, exceeds 29.5 degrees Celsius.

The report concludes that St. Maarten is likely to become hotter and drier, while continued sea-level rise will increase the threat of coastal flooding, storm damage and beach loss. It stresses that climate adaptation is needed now, particularly to protect water resources, strengthen infrastructure and help communities cope with increasing heat.

The scenarios are not presented as precise predictions, and the report does not identify one outcome as more likely than another. The eventual changes will depend largely on global greenhouse-gas emissions and how regional rainfall patterns respond to continued warming. However, the overall conclusion remains consistent across the scenarios.

By around 2050, the number of hot days could increase to between 85 and 136 annually, depending on global emissions. By 2100, the figure could range from 91 days under a low-emissions scenario to 249 days under high emissions. Under the most severe scenario, what is now considered extreme heat would occur for more than eight months of the year.

Average temperatures are projected to rise by approximately 0.8 to 1.3 degrees Celsius by 2050. By 2100, St. Maarten could be as much as 3.3 degrees warmer than the current climate.

The report states that warming will occur throughout the year, with the strongest increases expected during the wet season, which is already the hottest period. By the end of the century, the country’s annual average temperature could exceed the average temperature currently experienced during August, the hottest month of the year.

The effects are expected to extend beyond personal discomfort. Longer periods of extreme heat could increase health risks for older residents, children, outdoor workers and people with existing medical conditions. Higher temperatures could also increase electricity demand for air conditioning, place additional strain on infrastructure and intensify heat in densely developed communities.

The report also projects a generally drier future for St. Maarten. Current average annual rainfall is approximately 1,112 millimetres, but this could fall to about 600 millimetres by 2100 under the high-emissions, strong-drying scenario.

Most scenarios point to declining rainfall, although the severity differs. Under the strongest drying scenario, both the wet and dry seasons would receive less rain, the dry season would last longer and extremely dry years could become more severe. June and July, which normally fall within the wet season, could become part of an extended dry period.

A reduction of that scale would place additional pressure on water production and storage, agriculture, vegetation and natural habitats. Longer dry periods could also increase the risk of wildfires and leave the country more vulnerable when regional drought conditions occur.

Sea-level rise represents another major concern. Measurements show that the sea near St. Maarten rose by approximately 3.1 centimetres per decade between 1993 and 2023.

The report projects a further rise of approximately 21 to 23 centimetres by 2050. By 2100, sea level could rise between 46 and 78 centimetres, depending on future emissions. Higher sea levels would increase the reach and impact of waves and storm surges, particularly during hurricanes and other severe weather events.

The report also identifies a low-likelihood, high-impact possibility in which sea level could rise by as much as 3.4 metres by 2100 if instability in the Antarctic ice sheet makes a major contribution. It states that sea-level rise will continue beyond this century even if global warming stabilizes, making a rise of more than one metre a question of when, rather than whether, it will occur.

For St. Maarten, where significant housing, tourism properties, roads, utilities and other infrastructure are concentrated near the coast, the findings carry implications for land-use planning, construction standards, drainage, coastal protection and disaster preparedness.

The report was developed through cooperation involving the Meteorological Department of St. Maarten, the Royal Netherlands Meteorological Institute and the International Panel on Deltas and Coastal Areas. Its findings are intended to guide national climate adaptation planning and long-term decisions affecting infrastructure, public health, water security and coastal development.

Download St. Maarten's scenario here: Meteorological Department St. Maarten (MDS) Version - Meteorological Department St. Maarten (MDS)