🇯🇲Jamaica

Jamaica spans 17°43′–18°31′N as a Caribbean country of roughly 10,991 km² in the Greater Antilles, about 145 km south of Cuba. The island is dominated by a rugged mountainous interior — the Blue and John Crow Mountains in the east rising to Blue Mountain Peak at 2,256 m, the central Cockpit Country karst plateau, and the Dry Harbour Mountains — surrounded by narrow coastal lowlands including Kingston, Montego Bay, and Negril.

The climate is tropical maritime, ranging from tropical monsoon (Köppen Am) on the wet windward northeast coast at Port Antonio and Annotto Bay and the eastern mountain slopes, transitioning to tropical savanna (Aw) on the leeward south coast around Kingston and Mandeville and the dry Liguanea Plain.

Kingston averages 24°C in January and 28°C in July with about 800 mm of rainfall split into two seasons peaking in May and September through November. Montego Bay records 24°C in January and 28°C in July with 1,400 mm annually, while Port Antonio on the wet northeast windward coast sees 24°C and 28°C with 3,260 mm and no real dry season.

Negril averages 24°C and 28°C with 1,600 mm, and the Blue Mountains receive 5,000–7,500 mm with summit temperatures averaging a cool 13°C and occasional frost. Jamaica sits squarely in the Atlantic hurricane belt and has been struck repeatedly — Hurricane Charlie in 1951, Allen in 1980, the severe Hurricane Gilbert in September 1988 that made a direct Category 3 landfall and damaged roughly 50% of buildings, Ivan in 2004, Dean in 2007, Sandy in 2012, and Beryl in July 2024 which grazed the island as a Category 4 storm.

Recurrent severe multi-year Caribbean droughts, notably the 2014–15 event which was the worst in decades, intensifying coastal coral bleaching, accelerating sea-level rise threatening Kingston Harbour, and severe coastal erosion at Negril where more than 30 metres of beach have been lost in some sections are all central climate concerns.

Our archive covers 4 Jamaican cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Portmore, around 31°C, while Spanish Town records the coldest January nights near 22.4°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.5°C.